vxassist(1M) vxassist(1M)
NAME
vxassist - create, relayout, convert, mirror, backup, grow, shrink, delete, and move volumes
SYNOPSIS
vxassist [options] [-b] add column volume
[storage-spec ...] [attribute ...]
vxassist [options] [-b] addlog volume [attribute ...]
vxassist [options] [-b] add log volume [attribute ...]
vxassist [options] [-b] add mirror volume [attribute ...]
vxassist [options] [-b] [--noattach] -M add mirror volume ... [storage-spec ...] [attribute ...]
vxassist [-g diskgroup] [-b] [-O operation-tag] commit volume
vxassist [options] [-b] convert volume [attribute ...]
vxassist [options] [-b] evacuate
{column|disk|log|mirror|subdisk|volume}
volume [storage_spec ...] [attribute ...]
vxassist [options] [-b] growby volume lengthchange [attribute ...]
vxassist [options] -M growby
vxassist [options] [-b] growlogby volume
lengthchange [storage_spec ...] [attribute ..
vxassist [options] [-b] growlogto volume
lengthchange [storage_spec ...] [attribute ..
vxassist [options] [-b] growto volume newlength [attribute ...]
vxassist [options] -M growto
vxassist help { alloc | attrs | layout | mirror | options | showattrs | space | usage }
vxassist [options] list tag= tagname ...
vxassist [options] listattrs [lun_name1 [lun_name2 ...]]
vxassist [options] listtag {volume|vset}
vxassist [options] [-b] make volume length [attribute ...]
vxassist [options] -M make
vxassist [options] [-b] maxgrow volume [ attribute ...]
vxassist [options] [-b] maxsize [attribute ...]
vxassist [options] [-b] [-g diskgroup] [-P storage_pool] [-I rules] migrate volume ...
vxassist [options] -M migrate
vxassist [options] [-b] mirror volume [attribute ...]
vxassist [options] [-b] [--noattach] -M mirror volume ... [storage-spec ...] [attribute ...]
vxassist [options] [-b] [-k [-O operation-tag]] move volume
storage-spec ... [attribute ...]
vxassist [options] printintent [object_names ...]
vxassist [options] printrules volume ...
vxassist [options] [-b] relayout {volume|plex} [attribute ...]
vxassist [options] [-b] remove {column|log|mirror|volume}
volume [storage-spec ...] [attribute ...]
vxassist [options] [-b] -M remove mirror volume ...
[storage-spec ...] [attribute ...]
vxassist [options] removeall log volume
vxassist [options] removetag {volume|vset} tagname[=[tagvalue]] ...
vxassist [options] replacetag {volume|vset} old_tagname new_tagname
vxassist [-b] [-g diskgroup] reversemigrate volume ...
vxassist [-b] [-g diskgroup] reversemigrateall
vxassist [-g diskgroup] [-b] [-O operation-tag] rollback volume
vxassist [options] [-b] setstwidth volume [attribute ...]
vxassist [options] settag {volume|vset} tagname[= tagvalue] ...
vxassist [options] shrinkby volume lengthchange [attribute ...]
vxassist [options] -M shrinkby
vxassist [options] shrinkto volume newlength [attribute ...]
vxassist [options] -M shrinkto
vxassist [options] snapabort volume
vxassist [options] snapback snapvolume
vxassist [options] snapclear volume [snap_object]
vxassist [options] snapprint [volume]
vxassist [options] snapshot volume [snapvolume] [attribute ...]
vxassist [options] { -o allvols | -o site= sitename } [-o name= pattern] snapshot [attribute ...]
vxassist [options] [-b] snapstart [nmirror= number] volume [attribute ...]
vxassist [options] snapwait volume
vxassist [options] [-b] transform volume
[storage_spec ...] [attribute ...]
vxassist [options] transformreverse volume
vxassist [options] verify
DESCRIPTION
The vxassist utility is a command-line interface to the Veritas Volume Manager (VxVM) that:
o Finds space for and creates volumes
o Performs volume conversion
o Adds mirrors and logs to existing volumes
o Extends and shrinks existing volumes
o Migrates data from a specified set of disks
o Provides facilities for the online backup of existing volumes
Specify the appropriate keyword to vxassist to select an action to perform.
The vxassist utility also provides a command line interface to the Veritas Intelligent Storage Provisioning (ISP) feature of Veritas Volume
Manager (VxVM) that provides rule-based allocation of storage for the creation and administration of application volumes. If a storage
pool has been configured in a disk group, ISP volumes are created in it by default unless the -o nointent option is specified. If a disk
group does not contain a storage pool, non-ISP volumes are created in it by default unless the -o intent option is specified, which has the
side effect of also creating a storage pool. For operations on a disk group with a storage pool and one or more clone pools, the -P option
can be used to specify the pool on which to operate.
Note: Not all keywords, options and attributes are applicable to both ISP and non-ISP volumes. This is noted where applicable on this man-
ual page. The vxassist command returns an error if you try to perform an invalid operation on an ISP or non-ISP volume.
Each operation can be applied to only one disk group at a time. For most keywords, the volume operand specifies the volume on which to
operate. For the make operation, attributes that name specific disks can be used to determine a default disk group, according to the stan-
dard disk group selection rules described in vxintro(1M). A specific disk group can be specified with -g diskgroup. If this option is not
specified, and an alternate default disk group is not defined by specifying the diskgroup attribute on the command line or in a defaults
file (usually /etc/default/vxassist), the default disk group is determined using the rules given in the vxdg(1M) manual page.
Many vxassist operations can take a set of attributes that specify such things as how to lay out volumes, or on which sets of disks to
build them. There are two basic types of attributes:
o storage specifications
o attribute settings
Storage specification attributes are either simple disk names (for example, disk01), or groups of disks selected by a shared attribute such
as controller or target. For example, ctlr:c1 specifies all disks on controller 1.
You can exclude (negate) storage specification by specifying the exclamation character (!) prefix. (Note: You may also need to escape the !
character to prevent it being interpreted by the shell.) For example, you can combine the arguments ctlr:c1 and !target:c1t5 to indicate
that storage be allocated from controller 1, but not from SCSI target 5 on that controller.
Other attributes are of the form attrname= value; these additional attributes can specify the type of a volume (mirrored, RAID-5, striped,
logged), layout policies (contiguous, spanning), mirroring requirements (mirror across controllers), and constraint parameters (constrain
allocations to a single controller). See the ATTRIBUTES section below for a complete list of attribute specifications.
If no non-excluded storage specification attributes are given, any non-reserved, non-volatile, non-spare, non-excluded disk can be used to
allocate storage. Attributes may constrain the selection, particularly with respect to the selection of multiple disks. For example, the
command:
vxassist make mirvol 500m layout=mirror,log mirror=ctlr !ctlr:c2
requests that vxassist create a new mirrored volume on any disks that are not on controller 2. The mirror=ctlr attribute constrains the
selection of disks so that the mirrors are created on different controllers.
KEYWORDS
add column
Adds columns to a volume. Unless the number is specified, one column is added.
The addition of columns supports the specification of the following attributes: layout=grow, ncols, stripe_stripeunit, tmplen and
use_storage.
addlog Adds a log or DCO to a volume.
DCO is a data change object, used for Persistent FastResync. Note: This operation is only supported for version 0 DCOs.
DRL is a dirty region log, used for speedy recovery of mirrors after a system crash.
Sequential DRL is a form of DRL that is optimized for volumes that are written to sequentially, such as database log volumes.
Note: For volumes with version 20 DCOs, DRL and sequential DRL are supported within the DCO volume itself. You can specify the
dcoversion=20 attribute to the vxassist make command to create a volume with a version 20 DCO, or you can use the vxsnap prepare
command to add a version 20 DCO to a volume. You cannot use the vxassist addlog command to add a version 20 DCO to a volume.
DCM is a data change map, used for fast resynchronization of a secondary RVG with its primary.
Mirrored volumes are associated with DRL or sequential DRL logs.
RAID-5 volumes are associated with RAID-5 logs.
Replicated volumes are associated with DCM logs.
By default, when adding a log, vxassist attempts to determine the correct type of log to add, even if no logtype attribute is
specified. For example, if the volume is part of an RVG, vxassist attempts to create a DCM log.
When adding a DRL, RAID-5 or DCM log to a volume for the first time, the loglen attribute can be used to specify the length of
the log; on adding additional logs, the loglen attribute is ignored and the existing log length is used. If a loglen which is too
large or small to be practical is specified, vxassist may adjust the length to a reasonable size. If no loglen attribute is sup-
plied, vxassist picks an appropriate log size. Other attributes can be specified to indicate desired properties for the new allo-
cations. Mirroring constraints do not apply to logs, though storage constraints can be specified that limit the logs to disk sets
already used by the volume.
Adding a version 0 DCO to a volume creates a DCO object that is associated with the volume, and a DCO volume that is associated
with the DCO object. When created for a non-layered volume with at least 2 data plexes or for any layered volume, the default DCO
volume has 2 DCO plexes (mirrors for redundancy), each of length 132 blocks. When created for a non-layered volume with a single
data plex, the default DCO volume has a single unmirrored DCO plex of length 132 blocks.
Note: The actual length may be rounded up to the disk group alignment value (see vxdg(1M)).
Note: To allow operation of the dynamic disk group split/join feature (see vxdg(1M) for more information), vxassist attempts to
place version 0 DCO plexes on the same disks as the plexes of the corresponding data volume. This allocation policy may not suc-
ceed if there is insufficient disk space. vxassist then uses available space in the remaining disks of the disk group. This may
prevent certain disk group split or move operations if the DCO plexes cannot accompany their parent data volume. To overcome
this, you can use storage specifications to specify explicitly the disks on which the DCO plexes are to be configured.
Note: Adding a DCO does not enable Persistent FastResync on the parent volume unless fastresync=yes is also specified.
Adding a DRL log to a mirrored volume creates a single log subdisk and a new plex to contain that subdisk. The new plex is then
attached to the volume. Note: For volumes with version 20 DCOs, DRL is supported within the DCO volume itself. Dedicated DRL log
plexes should not be created for such volumes.
Adding a RAID-5 log to a RAID-5 volume involves creating a new plex that is attached to the volume as a log plex.
Adding a DCM log to a replicated volume adds two logs (by default), each consisting of a log plex and associated subdisk. DCM
logging can co-exist with DCO.
add log For ISP volumes, this operation is identical to the addlog operation.
Note: The add log operation is supported for ISP volumes only. For non-ISP volumes, use the addlog operation.
add mirror
For ISP volumes, this operation is identical to the mirror operation.
Note: The add mirror operation is supported for ISP volumes only. For non-ISP volumes, use the mirror operation.
commit Completes tentative subdisk move operations by removing the source subdisks, and replacing them with the target subdisks. The -O
option can be used to specify an operation tag for the subdisks whose tentative move is to be committed. If no operation tag is
specified, the commit operation is applied to all completed tentative subdisk moves for the named volume. The commit operation
fails if a tentative move or a recovery resynchronization is in progress.
convert Converts a volume layout to a mirror-stripe from a stripe-mirror, or from a mirror-stripe to a stripe-mirror. Also converts to
mirror-concat from a concat-mirror, or from a mirror-concat to a concat-mirror.
Note: This operation is not supported for ISP volumes.
evacuate {column|disk|log|mirror|subdisk|volume}
Relocates columns, disks, logs, subdisks, or mirrors that belong to the named volume, or moves an entire volume.
For disks, excluded storage may specified using the ! prefix.
The names of column, log, mirror and subdisk names may be specified by the attributes columnnames, lognames, plexnames and sd
respectively.
This operation also supports the use of the attributes evac_storage and use_storage to specify storage that is to be evacuated
and populated respectively.
growby | growto
Increases the length of the named volume to the length specified by newlength (growto), or by the length specified by length-
change (growby). Specify the new length, or change in length, in Veritas Volume Manager standard lengths (see vxintro(1M)) or as
a percentage (for example, 110%).
The growto operation fails if the new length is not greater than the current volume length. The length of the volume is
increased by extending existing subdisks in the volume, or by adding and associating new subdisks. Plexes that are not already
fully populated (that is, sparse) are left unchanged. Log-only plexes are also left unchanged.
Note: Following a relayout, specify the attribute layout=nodiskalign to the growby and growto commands if you want the subdisks
to be grown using contiguous disk space.
Note: When you grow a volume, it is recommended that you also grow any file system that is configured on that volume (see vxre-
size(1M)). vxassist does not resize file systems (or other uses of the volume, such as databases) that reside on the volume.
When a non-ISP volume is grown, its layout may be converted as a side effect if vxassist determines that the new volume is too
large for the original layout. The values of the stripe-mirror-col-trigger-pt and stripe-mirror-col-split-trigger-pt attributes
(by default, 1 gigabyte) control whether a new layout will be applied. A mirror-stripe volume that is larger than the value of
stripe-mirror-col-trigger-pt is converted to a stripe-mirror volume. If each column of a stripe-mirror-col volume is larger than
the value of stripe-mirror-col-split-trigger-pt, the volume is converted to a stripe-mirror-sd volume where the individual sub-
disks, rather than the columns, are mirrored. A mirror-concat volume that is larger than the value of stripe-mirror-col-split-
trigger-pt is converted to a concat-mirror volume where the individual subdisks, rather than the plexes, are mirrored.
If the new volume layout is inappropriate, use the vxassist convert operation to change the layout after the grow operation has
finished.
See Layout Specifications for a description of the methods used to determine disk layouts.
Note: The relayout operation requires all mirrors in a volume to have the same layout. If a mirrored volume is composed of mixed
plex layouts, relayout the mirror plexes to the same layout before attempting to relayout the volume.
You can specify attributes to indicate properties for the new allocations. Any mirroring constraints still apply between all
extensions to the existing mirrors and the other mirrors. Growing of a volume requires that the volume be enabled.
When the size of a replicated volume changes, you can ensure that the size of the DCM is appropriate by removing all the DCM logs
and adding them back without specifying the loglen attribute.
These operations can be applied to single volumes, or to multiple ISP volumes if the -M option is specified.
These operations support the specification of the following attributes: layout=contig, layout=span, spare, use_storage.
growlogby | growlogto
Increases the length of DCO volume associated with the named volume to (growlogto) or by (growlogby) the specified length in Ver-
itas Volume Manager standard units (see vxintro(1M)) or as a percentage (for example, 110%).
The growlogto operation fails if the new length is smaller than the current DCO volume length.
The logtype=dco attribute must be specified.
help Displays information on vxassist usage and Veritas Volume Manager attributes. For example, to display information about using
vxassist attributes, enter:
vxassist help attributes
list Lists all volumes in the disk group on which the specified tag has been set.
Dotted tag hierarchies are understood. For example, the listing for tag=a.b includes all volumes that have tag names that start
with a.b.
listattrs Lists the attribute tags of the logical units (LUNs) in the specified disk group and/or storage pool.
If LUN names are specified, only the attributes of those LUNs are displayed.
If the -a option is specified, the attributes of all LUNs that are attached to the host are displayed.
Otherwise, an error is returned if a disk group is not specified and no default disk group is defined (see the vxdg(1M) manual
page).
listtag Lists all the tag names and tag values that have been set on a volume or volume set.
make Creates a volume with the specified name and the specified length. The length is specified as a standard Veritas Volume Manager
length (see vxintro(1M)). You can specify attributes to indicate various properties and storage locations for the created vol-
ume. See Layout Specifications for a description of the methods used to determine disk layouts.
This operation can be used to create multiple ISP volumes if the -M option is specified. This allows the allocation of storage
to be balanced among the volumes that are created in the same operation. See the section Operations on Multiple Volumes for
details.
maxgrow Reports the maximum size a volume can grow given its attributes and given the free storage available.
maxsize Reports the maximum size a volume could be created with given the attributes specified and given the free storage available.
migrate Makes non-ISP volumes previously created using vxassist manageable by ISP. The volumes to be migrated from a disk group may be
specified on the command line, or in a definitions file that is read from the standard input if the -M option is specified. See
the section Operations on Multiple Volumes for details of the syntax of this file.
ISP assigns the default intent, "allocate plexes, logs and columns on separate disks" to the volumes that are being migrated.
You can specify additional rules using the -I option on the command line, or by entries in the definitions file. However, you
cannot include mirror, stripe or log rules. Rules specified on the command line are applied to all the specified volumes. The
use of a definitions file allows different rules to be applied to each volume.
Volumes specified on the command line are also associated with the same storage pool. If a storage pool is not specified using
the -P option, the volumes are placed in the data storage pool of the disk group. The use of a definitions file allows the
migrated volumes to be placed in different storage pools.
Note: Volumes to be migrated must be compatible with the Cross-platform Data Sharing (CDS) feature and have an alignment value of
8k. All volumes in a VVR replicated volume group (RVG) must be migrated together. All volumes that share a set of disks must be
migrated in a single operation. Disks cannot be shared with any volumes that are not listed on the command line or in a defini-
tions file. Volumes cannot share disks unless these disks are to be located in the same storage pool. Volumes with a usage type
of root, such as those on a root disk that is under VxVM control, cannot be migrated. The disk group containing the volumes to
be migrated must have a version number of 120 or greater (see vxdg(1M)).
mirror Creates a new mirror (or plex) and attaches it to the volume. This operation is allowed only if the volume is enabled.
Attributes can be specified to indicate various desired properties and storage locations for the created volume. Attributes that
constrain mirroring (such as requiring that mirrors be on separate groups of disks) apply between the existing mirrors of the
volume and the new mirror.
If the -M option is specified, mirrors may be added to several ISP volumes in a single operation. See the section Operations on
Multiple Volumes for details.
move Moves subdisks within the named volume off the excluded storage specified on the command line. Excluded storage is specified
with a prefix of !. The move operation requires that at least one excluded storage specification be given.
If the volume is enabled, subdisks within detached or disabled plexes (or detached log or RAID-5 subdisks) are moved without
recovery of data. If the volume is not enabled, stale log or RAID-5 subdisks, or subdisks within STALE or OFFLINE plexes, are
moved without recovery; if there are other subdisks within a non-enabled volume that require moving, the move operation fails.
For enabled subdisks in enabled plexes within an enabled volume, the data within subdisks are moved to the new location, without
loss of availability (or redundancy) of the volume.
If the -k option is specified, a subdisk move is initiated but the source subdisks are preserved on the original plexes, and the
source and target subdisks are marked. Such an operation is termed a "tentative move" operation, and can be committed or rolled
back at a later time. If the -O option is used to specify a tag, this tag can be used with the vxtask command to monitor, pause
or abort such operations.
printintent
Prints the rules, capabilities and volume templates that are associated with the specified objects. The types of object that can
be specified are disk groups, storage pools, volumes and plexes. If no object names are specified, the disk group is assumed as
the default object. This information may also be obtained by using the vxprint -m command. The only supported option is -g
diskgroup.
Note: This operation is only supported for ISP volumes.
printrules
Displays the complete set of rules that were used to create one or more volumes. This set of rules was obtained by processing
the capabilities, volume templates and rules that were specified when a volume was created. The only supported option is -g
diskgroup.
Note: This operation is only supported for ISP volumes.
relayout Changes a volume layout or properties. This operation changes the number of columns in a stripe or the stripe width of a volume.
It also converts a volume to or from RAID-5, concatenated-mirror, striped, striped-mirror or any similar layout.
Note: This operation is not supported for ISP volumes.
Note: The relayout operation internally generates unique data object names (for example, v2-Dp02) when it converts a volume to a
specified destination layout.
Note: Following a relayout, specify the attribute layout=nodiskalign to the growby and growto commands if you want the subdisks
to be grown using contiguous disk space.
After relayout to a layered form, a volume may be converted to a non-layered form. For example, to convert from a 4-column mir-
ror-stripe to a 5-column mirror-stripe, first relayout the volume as a stripe-mirror:
vxassist relayout vol1 nstripe=5
If you view the volume with vxprint during relayout, the volume shows several subvolumes that are used during the change, and a
more complex configuration than usual.
After the new column is added, the volume is in stripe-mirror layout. Use vxassist convert to convert back to a mirror-stripe
layout:
vxassist convert vol1 layout=mirror-stripe
Note: If the system crashes during relayout or conversion, the process continues when the system is rebooted. However, if the
crash occurred during the first stage of a two-stage relayout and convert operation, only the first stage is subsequently com-
pleted after rebooting. You must run vxassist convert manually to complete the second stage.
remove {column|log|mirror|volume}
Deletes columns, logs, or mirrors from a volume, or deletes an entire volume. Unless the number is specified, one column, log or
mirror is removed.
The removal of columns supports the specification of the following attributes: layout=shrink, ncols, stripeunit and tmplen.
The removal of logs supports the specification of the following attributes: logtype (mandatory), lognames, nlogs, remaininglog
and remove_storage.
Note: Specifying logtype=dco completely removes a version 0 DCO object, DCO volume and any snap objects that are associated with
the specified volume, and also disables FastResync on the volume. To remove a version 20 DCO and DCO volume, use the vxsnap
unprepare command.
The removal of mirrors supports the specification of the following attributes: nmirror, plexnames, remainingmirror and
remove_storage.
Note: When deleting a mirror or a log, storage that is not to be removed is specified using the ! prefix. Storage that is to be
removed is specified without this prefix.
For example, to remove a mirror on disk01, enter:
vxassist remove mirror vol01 !disk01
See vxplex(1M) for an example of an alternative method of removing a mirror from a volume.
The alloc=, nmirror=, and nlog= attributes also determine the number of mirrors or logs remaining after the remove operation com-
pletes. When the number of mirrors drops to 1, logs are also removed.
By default, vxassist removes 1 column, mirror or log as appropriate.
If the -M option is specified, mirrors may be removed from several ISP volumes in a single operation. See the section Operations
on Multiple Volumes for details.
removeall log
Deletes all logs of the type specified by the logtype attribute from a volume.
Note: This operation is only supported for ISP volumes.
removetag Removes the specified tags from a volume or volume set. If only a tag name is specified, a tag with a matching name is removed
regardless of its value. If a tag value is specified, a tag is only removed if both its name and value match. If tagname= is
specified without a tag value, a tag with a matching name is only removed if its value is null.
replacetag
Replaces the specified tag that is set on a volume or volume set.
reversemigrate
Converts ISP volumes to non-ISP volumes. The converted volumes permanently lose any intent that was associated with them when
they were ISP volumes, and the vxvoladm command cannot be used to administer the configuration of any associated storage.
The volumes that are specified on the command line must not share any disks with any volumes that are not listed on the command
line.
reversemigrateall
Migrates all ISP volumes in a disk group to non-ISP volumes. The converted volumes permanently lose any intent that was associ-
ated with them when they were ISP volumes, and the vxvoladm command cannot be used to administer the configuration of any associ-
ated storage.
rollback Reverses tentative subdisk move operations by removing the target subdisks, and leaving the source subdisks intact. The -O
option can be used to specify an operation tag for the subdisks whose tentative move is to be rolled back. If no operation tag
is specified, the rollback operation is applied to all completed tentative subdisk moves for the named volume. The rollback
operation fails if a tentative move or a recovery resynchronization is in progress.
setstwidth
Sets the stripe unit width for a striped or RAID-5 volume in Veritas Volume Manager standard units (see vxintro(1M)). The tmplen
attribute may be used in conjunction with this operation.
settag Sets one or more specified tags on a volume or volume set. If only a tag name is specified, the tag is applied with a null
value. If a tag value is also specified, the tag is set with that value. If a tag already exists with the same name, it is
overwritten.
Tag names and tag values are case-sensitive character strings of up to 256 characters. Tag names can consist of letters (A-Z and
a-z), numbers (0-9), dashes (-), underscores (_) or periods (.) from the ASCII character set. A tag name must start with either
a letter or an underscore. Tag values can consist of any character from the ASCII character set with a numeric value from 32 to
127.
The tag names "site", "udid" and "vdid" are reserved and should not be used. To avoid possible clashes with future product fea-
tures, it is recommended that tag names do not start with any of the following strings: "asl", "be", "isp", "nbu", "sf", "symc"
or "vx".
shrinkby | shrinkto
Decreases the length of the named volume to the length specified by newlength (shrinkto), or by the length specified by length-
change (shrinkby). Specify the new length, or change in length, in Veritas Volume Manager standard lengths (see vxintro(1M)) or
as a percentage (for example, 110%).
The shrinkto operation fails if the new length is not less than the current volume length.
The length of a volume is decreased by removing and shortening subdisks to leave each plex with the requested volume length. The
freed space can then be allocated for use by other volumes. Log-only plexes are left unchanged.
When a non-ISP volume is shrunk, its layout may be converted as a side effect if vxassist determines that the new volume is too
small for the original layout. The values of the stripe-mirror-col-trigger-pt and stripe-mirror-col-split-trigger-pt attributes
(by default, 1 gigabyte) control whether a new layout will be applied. A stripe-mirror volume that is smaller than the value of
stripe-mirror-col-trigger-pt is converted to a mirror-stripe volume. A concat-mirror volume that is smaller than the value of
stripe-mirror-col-split-trigger-pt is converted to a mirror-concat volume.
If the new volume layout is inappropriate, use the vxassist convert operation to change the layout after the grow operation has
finished.
See Layout Specifications for a description of the methods used to determine disk layouts.
Note: You cannot resize volumes comprised of different plex layouts. If you try to do so, an error message displays stating that
the volume contains differing layouts.
Caution: Data can be lost or corrupted if file systems or other organized data residing on a volume are not shrunk before shrink-
ing the volume. vxassist does not resize file systems (or other uses of the volume, such as databases) that reside on the vol-
ume. You can use the vxresize command to shrink file systems on the volume (see vxresize(1M)). Otherwise, use the appropriate
application command to adjust the layout of data in the volume before initiating the shrink operation. You must specify the -f
option to forcibly shrink volumes of usage type fsgen or raid5.
These operations can be applied to single volumes, or to multiple ISP volumes if the -M option is specified.
These operations support the specification of the following attributes: layout=contig, layout=nocontig, layout=span, spare,
use_storage.
snapabort Removes the mirror snapshot when a snapstart mirror has been started (and eventually completed).
Note: This operation is not supported for ISP volumes.
snapback By default, finds one plex in the snapshot volume that has the snap_rid field set, and attaches it to the original volume. If
the plex is the last in a volume, that volume is removed from the disk group.
Note: This operation is not supported for ISP volumes.
Note: The snapshot volume and the original volume must be in the same disk group.
If the -o allplexes option is specified, all snapshot plexes in the same disk group are reattached. Alternatively, if the nmir-
ror= number attribute is specified, only number plexes are reattached.
The direction of the resynchronization can be determined by specifying either resyncfromoriginal or resyncfromreplica as the
useopt argument to the -o option. To choose the original volume as the preferred copy of the data, use -o resyncfromoriginal.
To choose the replica as the preferred copy of the data, use -o resyncfromreplica.
Note: Always unmount the snapshot volume (if mounted) before using snapback. You must also unmount the original volume (if
mounted) before using the -o resyncfromreplica option.
snapclear Clears the FastResync map, removes any snap objects, and clears the snap_rid field of the volume.
Note: This operation is not supported for ISP volumes.
Note: snapback cannot be invoked after snapclear is used.
If Persistent FastResync is enabled and the original volume and the snapshot volume are in different disk groups, snapclear
removes the snap object and clears the FastResync map for the snapshot volume that corresponds to the snapshot object. To stop
tracking on the original volume for the snapshot volume, specify the snap object, snap_object, in the original volume that refers
to the snapshot volume. You must also run vxassist snapclear separately on the snapshot volume. For example, if myvol1 and
SNAP-myvol1 are in separate disk groups mydg1 and mydg2 respectively, the following command stops tracking on myvol1 with respect
to SNAP-myvol1:
vxassist -g mydg1 snapclear myvol1 SNAP-myvol1_snp
However, tracking is still enabled on SNAP-myvol1 with respect to myvol1. The following command turns this tracking off by speci-
fying the snap object, myvol1_snp, in SNAP-myvol1 that points to myvol1:
vxassist -g mydg2 snapclear SNAP-myvol1 myvol1_snp
If Persistent FastResync is enabled and the original volume and the snapshot volume are in the same disk group, snapclear removes
the snap records for both the original volume and the snapshot volume in addition to clearing their FastResync maps.
Note: Either of the two previous examples stops Persistent FastResync tracking for both the snapshot volume (SNAP-myvol1) and the
original volume (myvol1) if they are in the same disk group.
To support Non-Persistent FastResync and to be compatible with previous versions of VxVM, a single snapshot volume can be speci-
fied as the argument to snapclear, for example:
vxassist -g myolddg snapclear SNAP-myoldvol
snapprint Displays the associations between the original volumes and their respective replicas. If a volume is specified, output is dis-
played only for that volume. An error message is displayed if FastResync is not enabled on the volume.
Note: This operation is not supported for ISP volumes.
The following information is displayed:
o Name of the original volume.
o Names of all snapshot volumes.
o Length in blocks of the volume, detached plex, or snapshot plex.
o Percentage of the snapshot plex or detached plex that is considered to have been changed (dirty). For Non-Persistent Fas-
tResync, which keeps information about changed regions in a single map for the original volume and its snapshot volumes, the
%DIRTY value is the same for the original volume as for a snapshot volume even if writes are only made to the snapshot volume.
For Persistent FastResync, which maintains separate tracking maps for the original volume and each of its snapshot volumes,
the %DIRTY value is based only on what has been written to an individual volume.
In the following example, Persistent FastResync is enabled on volume v1, and Non-Persistent FastResync on volume v2. V and v
indicate the volume, DP and dp indicate detached plexes, and SS and ss indicate snapshot plexes.
# vxassist -g mydg snapprint v1
V NAME USETYPE LENGTH
SS SNAPOBJ NAME LENGTH %DIRTY
DP NAME VOLUME LENGTH %DIRTY
v v1 fsgen 20480
ss SNAP-v1_snp SNAP-v1 20480 4
dp v1-01 v1 20480 0
dp v1-02 v1 20480 0
v SNAP-v1 fsgen 20480
ss v1_snp v1 20480 0
# vxassist -g mydg snapprint v2
V NAME USETYPE LENGTH
SS SNAPOBJ NAME LENGTH %DIRTY
DP NAME VOLUME LENGTH %DIRTY
v v2 fsgen 20480
ss -- SNAP-v2 20480 0
dp v2-01 v2 20480 0
v SNAP-v2 fsgen 20480
ss -- v2 20480 0
snapshot Creates a new volume by taking one or more attached temporary mirrors (with state SNAPDONE) to use as its plexes. The nmirror=
number attribute can be used to specify the number of mirrors in a snapshot volume. At least number SNAPDONE plexes must be
available in the original volume. By default, one plex is used if nmirrors is not specified.
Note: This operation is not supported for ISP volumes.
The comment attribute may also be used to set the comment field for the snapshot volume.
The following are examples of the use of the nmirror and comment attributes:
vxassist snapshot nmirror=2
comment="mirrored snapvol for myvol" myvol snapvol
Some usage types attempt to synchronize any in-memory data associated with the volume (such as unwritten file system modifica-
tions) when the snapshot operation is done. In particular, if the fsgen usage type is used with a volume containing a Veritas
File System (VxFS), then cooperating procedures ensure that all file system data is consistently flushed to the volume. For hfs
and other file system types, the synchronization operation calls sync. This makes the snapshot a better image, but it may leave
some inconsistencies between in-memory file system data and the data residing on the backup image.
The snapshot command accepts more than one volume. All the given volumes are split atomically (in a single transaction). That
is, all the given volumes are relatively consistent as a result of taking the snapshot. If you specify the -o allvols, it is not
necessary to specify any volume names. vxassist attempts to create a sufficiently long vxplex command to take a snapshot of all
the volumes in the disk group. You can use the -o name= pattern option to generate names for the snapshot volumes. Otherwise,
the default name assigned to each snapshot volume takes the form SNAP%d-%v.
snapstart Creates a plex and attaches it to the named volume as a snapshot mirror. When the attach completes, the plex has state SNAPDONE
and is a candidate for selection by the snapshot operation. Attributes can be specified to indicate the desired properties of
the snapshot mirror.
Note: This operation is not supported for ISP volumes.
The nmirror= number attribute can be used to specify the number of snapshot plexes to be attached to a volume. By default, number
is 1.
Note: For this command, the nmirror= number attribute is specified before the volume name.
Note: To allow operation of the dynamic disk group split/join feature (see vxdg(1M) for more information), vxassist attempts to
avoid placing snapshot plexes on the same disks as the plexes of the original volume or the plexes of its associated DCO volume.
This allocation policy may not succeed if there is insufficient disk space. vxassist then uses any other available space in the
disk group. This may prevent certain disk group split or move operations if the snapshot plexes and their associated DCO plexes
cannot be physically separated from the plexes of the original volume or the plexes of its DCO volume. To overcome this, you can
use storage specifications to specify explicitly the disks on which the snapshot plexes are to be configured.
snapwait Waits for an attached mirror to become available on a volume if a snapstart mirror attach is done as a background task (such as
using the -b option). The operation exits when the snapshot is complete. Available snapshot plexes are flagged with state SNAP-
DONE.
Note: This operation is not supported for ISP volumes.
transform Changes the capabilities of the existing volume online without changing the size of the volume. This operation supports all the
attributes and options that are supported by the make operation.
Note: The online transformation of an ISP volume is not necessarily complete if the vxtask command shows that synchronization of
the volume has finished. A small additional time is required to perform cleanup operations.
Note: This operation is supported for ISP volumes only.
transformreverse
Converts a volume that is undergoing a transformation back to its original state.
Note: If volume is undergoing a transformation, the vxtask list command shows that a synchronization task is being performed on
the top-level volume.
Note: This operation is supported for ISP volumes only.
verify Checks the intent of volumes that have been created by vxassist for conformance to template rules, user-specified rules, volume
group rules and storage pools rules. Error messages are displayed if the intent has been violated.
If the -a option is specified, the intent of all ISP application volumes in all disk groups is verified. Otherwise, the -g
diskgroup option can be used to verify the intent of all application volumes in the specified disk group.
Note: This operation is supported for ISP volumes only.
OPTIONS
-a When used with the listattrs keyword, lists the attributes of all LUNs that are attached to the host.
When used with the verify keyword, verifies the intent of volumes in all disk groups.
-b Performs extended operations in the background. This option applies to plex consistency recovery operations for make, growto and
growby, to plex attach operations started by mirror and snapstart, to relayout operations started by relayout, and to the addlog,
convert, maxgrow, maxsize, move and remove operations.
-d defaults
Specifies a file containing defaults for various attributes related to volume creation and space allocation. If not specified,
this defaults to /etc/default/vxassist.
-f
--force Forces operations not usually allowed by vxassist.
-g diskgroup
Specifies the disk group for the operation, either by disk group ID or by disk group name. If this option is not specified, and
an alternate default disk group is not defined by specifying the diskgroup attribute on the command line or in a defaults file
(usually /etc/default/vxassist), the default disk group is determined using the rules given in the vxdg(1M) manual page.
-k Initiates a subdisk move while preserving the source subdisks on the original plexes. The source and target subdisks are marked.
Such an operation is termed a "tentative move" operation, and can be committed or rolled back at a later time. If the -O option
is used to specify a tag, this tag can be used with the vxtask command to monitor, pause or abort such operations.
-M Performs the operation on multiple volumes. See the section Operations on Multiple Volumes for details.
Note: This option is supported for operations on ISP volumes only.
-n Prevents the system defaults file being read.
--noattach
When used with the -M option and the mirror or add mirror operations to add mirrors to a volume, indicates that the newly added
mirrors are to remain in the disabled state.
Note: This option is supported for ISP volumes only.
-o useopt Passes in options specific to a usage type to the operation. A certain set of operations are expected to be implemented by all
usage types:
allplexes Specifies that all available snapshot plexes in a disk group are to be reattached to their original volume during a
snapback operation.
allvols Takes a snapshot of all the volumes in the disk group. An error results if one or more volumes do not have a plex that
is usable for the snapshot.
intent Allows the creation of ISP volumes in a disk group that does not contain a storage pool. A storage pool is set up in
the disk group with an autogrow policy of diskgroup and a selfsufficient policy of host. By default, a non-ISP volume
would be created in such a disk group.
Note: Once a storage pool has been created, all volumes that are subsequently created in the disk group are ISP volumes
unless the -o nointent option is specified.
iosize= size
Performs copy and recovery operations in regions with the length specified by size, which is a standard Veritas Volume
Manager length number (see vxintro(1M)). Specifying a larger number typically causes the operation to complete sooner,
but with greater impact on other processes using the volume. The default I/O size is 1 megabyte.
name= pattern
Specifies the template for naming new snapshot volumes. The pattern consists of characters and one or more of the fol-
lowing specifiers:
%% Single percent character.
%d Unique serialization number expressed as a decimal integer.
%g Disk group name.
%m Mirror's original name.
%s Serialization string expressed as a sequence of one or more lower case letters.
%S Serialization string expressed as a sequence of one or more upper case letters.
%v Volume name.
%x Unique serialization number expressed as a lower-case hexadecimal integer.
%X Unique serialization number expressed as an upper case hexadecimal integer.
The default template name for a new snapshot volume is SNAP%d-%v.
nointent Allows the creation of non-ISP volumes in a disk group that contains a storage pool. By default, an ISP volume would
be created in such a disk group.
numchild= number
Specifies the number of child processes that are used to perform resynchronization during a snapback operation. The
default value of number is 1 (no child processes), which is the same as specifying a number of 0. Specifying a larger
value for number potentially speeds up resynchronization, although the effectiveness of this depends to some extent on
the underlying characteristics of the disk array. No further benefit in performance may be noticeable for a value for
number greater than 3.
By default, the child processes divide the volume into equally sized chunks, which they then resynchronize indepen-
dently with the volume. This behavior may be modified using the useopt sequential.
Note: A large iosize of 1m or 2m is recommended for use with this option.
ordered Specifies that ordered allocation should be used to create a new volume. For more information, see the Ordered Alloca-
tion section below.
readonly Specifies that a read-only replica volume is created during a snapshot.
renamesnapplex
Specifies that a snapshot plex is renamed when the snapshot operation is used to create a snapshot volume. If this
option is not specified, the plex retains the same name that it had in the original volume.
resyncfromoriginal
Performs a resync using the data in the original volume during a snapback.
resyncfromreplica
Performs a resync using the data in the snap plex during a snapback.
sequential
When specified with the useopt numchild for values of number greater than 1, the child processes co-operate in resyn-
chronizing regions of the volume that are close together, starting at the beginning of the volume and moving to the
end. This creates more overhead for the resynchronization, but it potentially makes better use of the sequential read-
ahead buffer of the physical disks.
site= sitename
When specified with the snapshot operation, a snapshot is created from all volumes in the disk group that have a pre-
pared snapshot plex in the SNAPDONE state at the specified site. The site: sitename2 storage allocation attribute can
be used to specify storage at a different site. You can use the -o name= pattern option to generate names for the
snapshot volumes. Otherwise, the default name assigned to each snapshot volume takes the form SNAP%d-%v.
slow[= iodelay]
Reduces the impact on system performance of copy operations. Copy and plex consistency recovery operations are usually
a set of short operations on small regions of the volume (typically 1 megabyte). This option inserts a delay between
the recovery of each such region. A specific delay can be specified with iodelay as a number of milliseconds, or a
default is chosen (normally 250 milliseconds).
-O operation-tag
Specifies an operation tag that can be used to commit or roll back a completed tentative move operation. If an operation tag is
specified for a tentative move operation, a task tag is automatically set to the same value. However, setting a task tag does
not imply the setting of an operation tag.
-p Prints only the maximum size with no text wrappers (used with maxsize and maxgrow).
-P storage_pool
Specifies the name of the storage pool to which an operation is applied. If a disk group contains only a data storage pool, this
option is not required. If a disk group contains a data storage pool and one or more clone storage pools, it may be necessary to
specify this option.
Note: This option is supported for operations on ISP volumes only.
-r Includes spare disks (reserved for hot-relocation) in the calculation.
-t tasktag
Marks any tasks that are registered to track the progress of an operation with the tag tasktag. This option is passed to utili-
ties called by vxassist, so any child tasks are also tagged with tasktag. The tag specified by tasktag is a sequence of up to 16
alphanumeric characters.
-U usetype
Limits the operation to volumes that have this usage type. Any attempt to operate on volumes that have a different usage type
fails.
For a make operation, this option specifies the usage type of the volume to be created. Otherwise, the default usage type set in
the /etc/default/vxassist file is used, or if such an entry does not exist, the usage type is set to fsgen.
-v Traces calls to other utilities to determine which Veritas Volume Manager commands vxassist is executing.
Hardware-Specific Options
Some environments provide guidelines to optimize VxVM's interaction with intelligent storage systems. If these guidelines are present, VxVM
follows the guidelines when creating volumes or allocating space for volumes. By default, vxassist only creates volumes that conform with
these guidelines. The following options change the behavior of vxassist operations make, mirror, grow and shrink :
-o override
Performs the specified vxassist task for the specified volume and ignores any storage-specific guidelines. Overriding the guide-
lines is not recommended as it can result in incompatible objects, or objects that cannot be administered by VxVM and any associ-
ated software that exploit storage-specific features.
-o verify Verifies that the vxassist task for the specified volume can be performed without violating any storage-specific guidelines, but
does not commit or perform any task. If any guidelines are violated, vxassist exits with an error message.
Note: These options need a separate license. Without the license, vxassist ignores the specified option.
Refer to the vendor-specific documentation for more information on how intelligent storage systems can interact with VxVM.
ATTRIBUTES
Attribute values for operations on volumes can be specified with arguments of the form attribute= value. Attributes can also be passed in
through a defaults file.
Default attribute values for operations on non-ISP volumes can be stored in the file /etc/default/vxassist. Default attribute values for
operations on ISP volumes can be stored in the file /etc/default/allocator. (The /etc/default/allocator_readme file contains a pristine
copy of the /etc/default/allocator file as it is shipped and installed.)
Attributes are selected according to the order in which they are scanned. In general they are taken in decreasing priority of being speci-
fied on:
1. The command line.
2. The specified defaults file (as supplied with the -d command line argument).
3. The system defaults file (as specified in /etc/default/vxassist or /etc/default/allocator as appropriate).
Attributes from all sources have the same form. However, in some cases, command-line attributes change default behaviors in ways that
attributes in the defaults file do not. In particular, references to mirroring (such as specifying a mirror count) or logging (such as
specifying a log count or length) on the command line cause mirroring or logging to happen by default. If such attributes are specified in
a defaults file, they indicate the attributes that would be used if mirroring or logging were enabled.
Attributes are either storage specifications (possibly negated), or are in the form attribute= value. In a defaults file, attributes are
separated by a space or are on separate lines. Blank lines in a defaults file are ignored, and comments can be included with the standard #
convention.
Storage Specifications
Storage specification attributes have one of the following forms:
[!]diskname
Specifies (or excludes) a disk. diskname refers to a disk media record name in a Veritas Volume Manager disk group.
[!]diskclass: instance
Specifies (or excludes) a set of disks. diskclass names a particular type of disk grouping (for example, ctlr to indicate groups
of disks on a single controller), and instance specifies which grouping of that type (for example c1). Each type of disk class
has a particular format for specifying instances of the class.
diskclass:same
Specifies that the allocation must be constrained to include disks from the same instance of the given class. For example, a
storage specification of diskparam:same indicates that all disks selected must have the same basic parameters (tracksize, cylin-
der size, size, and revolutions-per-minute), but does not specify which specific parameters to use.
The defined disk classes (and alternate names, or aliases, for those classes) are as follows:
ctlr (alias: c, ctrl, cntrl, controller)
Specifies disks accessible through a controller group. All disks accessible through the specified controller name(c#) are
selected for the operation.
For example, consider a configuration where two enclosures are connected to a host. The first through controllers c1, c2 and the
second through controllers c3, c4. The command:
vxassist make vol1 1024 !ctlr:c1
results in disks from the first enclosure being excluded from the operation because all disks in the first enclosure are accessi-
ble through c1(and c2). The command:
vxassist make vol1 1024 !ctlr:c2
has the same effect (of excluding disks in the first enclosure) in the above configuration. The command:
vxassist make vol1 1024 layout=mirror nmirror=2 mirror=ctlr
results in the mirrors being placed across the controller groups c1, c2 and c3, c4.
da Specifies a Veritas Volume Manager disk (VM disk) by device name (disk access record name). For example, c2t1d0 indicates a VM
disk defined on disk c2t1d0.
device (alias: d)
Specifies all VM disks on a physical disk. The physical disk is specified in the form c #t #d #, which indicates the controller,
target ID, and disk number. Typically, only one VM disk device is created for each physical disk.
diskgeom (alias: geom)
Specifies disks with a particular geometry. The geometry is specified in the form cyls.heads.sectors, to indicate the number of
cylinders, heads, and sectors per track, of the disk. Many modern drives have variable geometries (or geometries that do not fit
the standard conventions). For such drives, the geometry parameters used are whatever the drive reports.
Note: The diskgeom attribute is not supported for EFI disks.
diskparam Specifies disks with particular parameters. The parameters are specified in the form cyls.heads.sectors.rpm, to indicate cylin-
ders, heads, sectors per track, and the number of revolutions per minute of the drive. As with the diskgeom parameter, the
instances of the diskparam disk class depend upon the values reported by the drive, and may not be accurate.
Note: The diskparam attribute is not supported for EFI disks.
diskrpm (alias: rpm)
Specifies disks with a given rotation speed in revolutions per minute (for example, 7200).
dm (alias: disk)
Specifies a VM disk by disk name (disk media record name) in the disk group of the volume. Specifying a disk class type of dm or
disk is equivalent to giving a storage specification with no disk class name.
enclr (alias: e, enclr, enclosure)
Specifies disks belonging to a particular enclosure. The enclosure name is obtained using the command:
vxdmpadm listenclosure all
For example, the following command excludes disks in the enclosure enc1 from the operation.
vxassist make vol1 1024 layout=mirror nmirror=2
!enclr:enc1
site Specifies disks for which the same site name has been defined. For example, the following command only uses disks from the site
building1.
vxassist make vol2 2048 layout=mirror site:building1
The site name is propagated to all subdisk, plex and log plex records in a volume.
target (alias: t)
Specifies disks with the same SCSI target address on the same controller. The target is specified in the form c #t #. For exam-
ple, t:c2t4 selects disks on target 4 of controller 2.
The diskgeom and diskparam attributes are most often used in the form diskgeom:same and diskparam:same, to indicate that all disks used for
creating a volume should have similar characteristics.
For operations on ISP volumes, storage can additionally be specified using the following expressions in conjunction with rules that may be
combined by using the allof, eachof and noneof operators (see the OPERATORS section):
evac_storage= rules
Specifies storage assigned to a volume that is to be evacuated by the evacuate operation on columns, disks, logs, mirrors or sub-
disks.
remove_storage= rules
Specifies storage that is to be removed from use by a volume in a remove operation on a column, log or mirror.
use_storage= rules
Specifies storage that may be used to relocate columns, disks, logs, mirrors, subdisks or a volume that are being evacuated.
The following example evacuates data from subdisks belongs to the volume vol1 that are currently on controller c1 to available storage on
any other controller:
vxassist -g mydg evacuate sd vol1
evac_storage='eachof("Controller"="c1")'
use_storage='noneof("Controller"="c1")'
The next example creates a 10-gigabyte volume using disks from enclosure encl1 that are not available exclusively on controller c1:
vxassist -g mydg make vol2 10g
use_storage='allof("Enclosure"="encl1",noneof("Controller"="c1"))'
Note: The storage specification does not contribute to the intent of a volume.
Other Attributes
Other attributes are of the form attribute= value. The attribute name in an attribute value pair never contains a colon, so it is possible
to specify a disk that has an equal sign in its name using the storage specification dm:disk01=a. Without the dm: prefix, disk01=a would
cause an error indicating an unrecognized attribute.
Defined attributes (and common aliases) are:
alloc= storage-spec[,storage-spec,...]
Specifies storage as single attributes. This is useful in a defaults file, so that all attributes (including storage specifica-
tions) are in the attribute= value format. Any number of storage specifications can be specified, separated by commas. More than
one alloc attribute can be specified, in which case they are logically concatenated to form one longer list.
allocation_policy_order={1|2|3|4|5|6|7|8|9|10|11|12}
Specifies the order of priority in which ISP takes action to allocate space. For example, this attribute determines if growing
the storage pool is preferred to dropping the desired rules when there is insufficient storage to create a volume. The numeric
argument to allocation_policy_order determines the behavior of ISP as follows:
1 S < T < A < D
2 S < T < D < A
3 S < A < T < D
4 S < D < T < A
5 S < A < D < T
6 S < D < A < T
7 A < S < T < D (default behavior)
8 D < S < T < A
9 A < S < D < T
10 D < S < A < T
11 A < D < S < T
12 D < A < S < T
Here A stands for "autogrow," D for "desired rules," S for "self-sufficient," and T for "template combinations." The < operator
indicates the precedence, so that "X < Y" means that Y is chosen in preference to X, and the rightmost items in the list are cho-
sen before those to the left. For example, the default behavior of ISP (equivalent to allocation_policy_order=7), "A < S < T <
D," means:
T < D
First, drop desired rules in preference to using a different template combination.
S < T
Next, use a different template combination in preference to adding more templates to the storage pool.
A < S
Finally, add more templates to the storage pool in preference to growing the storage pool.
Note: This attribute is supported for operations on ISP volumes only.
allsites={on|off}
If multiple sites have been configured for a disk group (see vxdg(1M)) and allsites is set to on, storage for separate plexes is
allocated at all the sites for a volume that is being created.
If allsites=off is specified, separate plexes need not be configured at all the sites.
Note: The allsites attribute must be set to off for RAID-5 volumes in a site-consistent disk group.
autogrow={on|off|true|false|yes|no}
Enables or disables the autogrow feature for a cache volume that is used by space-optimized instant snapshots.
Note: This attribute is supported for operations on ISP volumes only.
cachevolume= cachevol
Specifies the cache volume that a space-optimized instant snapshot is to use.
Note: This attribute is supported for operations on ISP volumes only.
capability='cap_name(var_name= var_value, ...),cap_name ...'
Specifies the capabilities to be used with a make, maxsize, or transform operation. Capabilities take optional parameters, and
multiple capabilities can be specified for a volume.
See the Veritas Storage Foundation Intelligent Storage Provisioning Administrator's Guide for a list of the set of capabilities
that are provided by Veritas Volume Manager.
Note: This attribute is supported for operations on ISP volumes only.
col_switch= size1,size2[,...]
When creating a volume using ordered allocation (-o ordered), specifies how much space to allocate from each listed disk to a
concatenated column before switching to the next disk. The number of size arguments (switch points) determines how many disks
are concatenated to form a column. size1 space is allocated from the first disk, size2 space is then allocated from the second
disk, and so on. The switch points are applied identically to all columns in the volume being created.
For more information, see the Ordered Allocation section below.
comment= comment
Specifies a comment to give to a volume when it is created. This comment can be displayed with vxprint -l, and can be changed, at
a later time, with vxedit set. This attribute can be used with the make and snapshot operations.
columnnames= plex-name
(alias: column, columns) Specifies the name of columns for an evacuate operation.
dcolen= number (alias: dcologlen)
Specifies the length of each plex in a version 0 DCO volume. By default, specifying a length on the command line creates a DCO
volume. The default length is 132 blocks, and any specified value should be an integral multiple of 33 blocks between 33 and
2112 blocks.
Note: The actual length may be rounded up to the value of the disk group alignment (see vxdg(1M)).
dcoversion={0|20}
Specifies the type of DCO and DCO volume to be created for a volume when using the make command. A version 0 DCO supports Persis-
tent FastResync. A version 20 DCO supports Persistent FastResync, instant snapshots, and DRL and sequential DRL logs within the
DCO volume. If not specified, the default DCO version is 0.
Creating a version 20 DCO associates a DCO object with a volume, and associates a DCO volume with the DCO object. When created
for a non-layered volume with at least 2 data plexes or for any layered volume, the default DCO volume has 2 DCO plexes (mirrors
for redundancy) with a default region size of 64KB. A different region size can be specified by using the regionsz attribute.
diskgroup= disk-group (alias: dg)
Specifies the disk group for an operation. If a disk group is specified in a defaults file, then it just specifies the default
disk group to use for the make operation, if no other means of determining the disk group can be used. If specified as a command
line attribute, it has the same effect as specifying a disk group with the -g option (the operation is forced to apply to the
given disk group).
excl=yes|y|on|true|no|n|off|false
Sets or clears the EXCLUSIVE flag on the volume. A volume in exclusive open state can be opened by only one node in the cluster
at a time. Multiple opens of an exclusive volume from the same node are permitted. Non-exclusive volumes can be simultaneously
opened by more than one node. After a node opens an exclusive volume, every other node's open attempt fails until the last close
of the volume by the first opener. Such an open failure returns a EBUSY error code.
Note: Only available if the Veritas Volume Manager cluster feature is enabled.
fastresync=yes|y|on|true|no|n|off|false (alias: fmr)
Enables or disables both Persistent and Non_Persistent FastResync. If enabled, FastResync is non-persistent if a DCO object and
a DCO volume are not associated with a volume, and it is persistent if a DCO object and DCO volume are associated with a volume.
Note: A license is necessary to use the FastResync feature.
fstype= file-system-type
Specifies the file system type for a new volume (this is used only with the make operation). The file system type for a volume
is usually determined when needed by running the fstyp utility (see fstyp(1M)), but can be specified explicitly. The file system
type parameter is used with the Veritas Volume Manager vxresize utility, as well as with volume snapshots, copies, and dissoci-
ates (to select features that are used with Veritas File System (VxFS)).
The file system type can be changed at any later time with the vxedit set operation.
group= owning-group
Sets the group ID for a new volume. The group ID can be specified numerically or with a system group name. This attribute is used
only with the make operation. By default, volumes are created with group 0.
growby= growby-percentage
Sets the growby value as a percentage for a cache volume that is used by space-optimized instant snapshots.
Note: This attribute is supported for operations on ISP volumes only.
highwatermark= high-water-mark-percentage
Sets the high watermark value as a percentage for a cache volume that is used by space-optimized instant snapshots.
Note: This attribute is supported for operations on ISP volumes only.
init= initialization-type
Specifies how to initialize a new volume. The default method (which can be selected explicitly with init=default) is to call
vxvol start to perform a default initialization that is specific to a usage type. A new volume can be left uninitialized with
init=none. The most useful non-default initialization that can be specified is init=zero, to clear the volume before enabling it
for general use.
layout= layout-spec[,layout-spec,...]
Specifies a plex layout type (RAID-5, mirrored, unmirrored, striped, cylinder alignment), and turn some features on and off (such
as logging). The list of layout specifications is given in the Layout Specifications section. By default, unmirrored, non-
striped volumes are created without a log.
For ISP volumes, the arguments to the layout attribute are automatically converted into rules.
logdisk= disk[,disk,...]
When creating volumes using ordered allocation (-o ordered), specifies on which disks logs should be created. This attribute
must be specified for RAID-5 volumes unless nolog or noraid5log is specified. For other types of volume layout, this attribute
is optional, and if not specified any required logs are co-located with the data.
For more information, see the Ordered Allocation section below.
loglen= length
Specifies a log length to use for dirty-region log (DRL) subdisks for mirrored volumes, for RAID-5 log plexes, or for DCM log
plexes for replicated volumes. By default, specifying a log length on the command line creates a log. Associating a log with a
mirrored or RAID-5 volume is sufficient to enable its use.
A DCM log must be enabled using the vxrlink command. This is because it is used for failure recovery and synchronization of
replicated volumes.
logtype= type
Specifies the type of log to use with a mirrored or replicated volume:
dcm Select DCM (data change map). This is the default log type for replicated volumes.
dco Select DCO (data change object). (This is used to implement Persistent FastResync, which is enabled by additionally speci-
fying fastresync=on.) This creates a DCO object and a DCO volume with a plex size specified by the dcologlen attribute, and
number of plexes specified using the ndcomirror attribute. The default names for the DCO object and DCO volume are vol_dco
and vol_dcl respectively for a volume, vol.
If additional logging is required, it can be added to a volume by using the vxassist addlog command. DCO can co-exist with
DCM logging for replicated volumes, or with DRL logging for mirrored volumes.
Note: Additional version 20 DCO maps can be added by using the vxsnap addmap command.
drl Select DRL (dirty region logging). This is the default log type for mirrored volumes.
Note: For volumes with version 20 DCOs, DRL is supported within the DCO volume itself.
drlseq
Select sequential dirty region logging. This is identical to drl except that the number of dirty bits that can be set in
the DRL is limited to the value of the tunable voldrl_max_seq_dirty (default value is 3). This is useful on volumes that
are usually written to sequentially, such as database log volumes. Limiting the number of dirty regions allows for faster
recovery if a crash occurs. However, if applied to volumes that are written to randomly, this type of logging can be a per-
formance bottleneck as it limits the number of parallel writes that can be carried out.
Note: For volumes with version 20 DCOs, sequential DRL is supported within the DCO volume itself.
none Do not create a log.
region
Select dirty region logging; identical to drl.
RAID-5 logging is automatically selected when a log plex is added to a RAID-5 volume; it has no specific logtype.
If logtype is not specified for a volume, vxassist attempts to create the optimal type of log.
logmap_len= size
Specifies the maximum usable size in bytes of a DRL log to the addlog or make operations. This value is not constrained by any
disk group alignment value.
max_nraid5column= number
(alias: maxraid5columns, max_nraidcolumn, max_nraid5stripe, max_nraidstripe, maxraidcolumns, maxraid5stripes, maxraidstripes)
Specifies the default maximum number of stripe columns for a RAID-5 volume (default value is 8 for non-ISP volumes, and 15 for
ISP volumes). The rules for selecting the default number of RAID-5 stripe columns are described in the nstripe attribute.
max_ncolumn= number (alias: maxcolumns, max_nstripe, maxstripes)
Specifies the default maximum number of stripe columns, either for a RAID-5 volume (if max_nraid5stripe is not also specified) or
for a striped plex (default value is 8 for non-ISP volumes, and 15 for ISP volumes). The rules for selecting the default number
of stripe columns is described in the nstripe attribute.
max_regionloglen= length (alias: maxregionloglen)
Specifies the maximum default dirty region logging log subdisk length. If the user does not specify the dirty region log length
for a volume, when creating the first log for a mirrored volume, vxassist uses a simple formula based on the log length. The
default length is not be bounded by max_regionloglen (default value is 32k (32 kilobytes)).
maxgrow= maxgrow-percentage
Sets the maxgrow value as a percentage for a cache volume that is used by space-optimized instant snapshots.
Note: This attribute is supported for operations on ISP volumes only.
min_ncolumn= number (alias: mincolumns, min_nstripe, minstripes)
Specifies the default minimum number of stripe columns for either a RAID-5 volume (if min_nraid5stripe is not also specified) or
for a striped plex (default value is 2). The policy for selecting a default number of stripe columns is not allowed to select
fewer than this number of columns.
min_nraid5column= number
(alias: minraid5columns min_nraidcolumn, min_nraid5stripe, min_nraidstripe, minraidcolumns, minraid5stripes, minraidstripes)
Specifies the default minimum number of stripe columns for a RAID-5 volume (default value is 3 for non-ISP volumes, and 2 for ISP
volumes). The policy for selecting a default number of RAID-5 stripe columns is not allowed to create a RAID-5 volume with fewer
than min_nraid5stripe stripe columns.
Note: It is notionally possible to create a RAID-5 volume with 2 columns in VxVM. This is effectively a 2-way mirror with reads
directed to alternate stripe units on the two columns. This can improve read performance over that of a unstriped 2-way mirror.
However, such a layout is usually much more inefficient in CPU usage when writing to the volume and is not generally recommended.
mirror=[+|-]number|yes|no|diskclass[,...]
Specifies various mirroring parameters. Multiple mirroring parameters can be given, each separated by a comma. A decimal number
indicates a specific number of mirrors to create, when creating a mirrored volume (equivalent to nmirror= number). yes indicates
that volumes should be mirrored by default (equivalent to layout=mirror). no indicates that volumes should be unmirrored by
default (equivalent to layout=nomirror).
Any other mirroring parameters specify that volumes should be mirrored across instances of a particular disk class (such as ctlr,
enclr, site or target). For example, mirror=target specifies that volumes should be mirrored between SCSI target addresses, and
mirror=ctlr specifies that disks in a mirror should not be on the same controller as disks in other mirrors within the same vol-
ume. Similarly, mirror=enclr specifies that disks in a mirror should not be from the same enclosure as disks in other mirrors
within the same volume. Similarly, mirror=site specifies that the disks in a mirror should not be at the same site as other mir-
rors in the same volume.
Each mirror can contain disks from any number of instances of the disk class, but different mirrors cannot use disks from the
same instance of the disk class.
mirrorconfine= diskclass[,diskclass,...]
Specifies a required list of disk classes for mirror confinement constraints. If this attribute is specified, a single mirror is
confined to (that is, allocated from) a group of disks belonging to a specific disk class. Multiple mirrors can be allocated
from a single disk class. Multiple disk classes cannot be used to allocate a mirror. The following example specifies that each
mirror is allocated from devices belonging to a single SCSI target; and multiple mirrors can be allocated from devices belonging
to a single SCSI target:
mirrorconfine=scsi_target
mode= permissions
Specifies the permissions for the block and character device nodes created for a new volume. The mode can be specified either as
an octal number or symbolically. A symbolic mode is specified using the syntax given in chmod(1). This attribute is used only
with the make operation. The default mode for a volume gives read and write access only to the owner.
ndcmlog= number (alias: ndcmlogs, ndcms, ndcm)
Specifies the number of DCM log plexes to create. The default number is 2 which creates a mirrored DCM log.
ndcomirror= number (alias: ndco, ndcos, ndcolog, ndcologs, ndcomirrors)
Specifies the number of DCO plexes to create for a DCO volume. A value for number of 2 or greater creates a mirrored DCO volume.
For non-layered non-ISP volumes, the default number is set to the lesser of the number of data plexes in the parent volume or 2.
For layered non-ISP volumes, the default value is 2. For ISP volumes, the default value is 1.
nlog=[+|-]number, (alias: nlogs, logs)
Specifies the number of logs to create, by default, for a RAID-5, mirrored, or replicated volume (assuming that logs are to be
created). The number of logs to create can be specified independently for RAID-5 or mirrored volumes using the nraid5log and nre-
gionlog attributes. For a relayout, this value can be preceded by a + or a - to add or subtract logs.
nmirror=[+|-]number, (alias: nmirrors, mirrors)
Specifies the number of mirrors to create when mirroring a volume (default value is 2).
For a relayout, this value can be preceded by a + or a - to add or subtract mirrors. The value can also be specified as src_nmir-
ror to preserve the number of mirrors.
This attribute is also used to specify the number of snapshot plexes to be attached to a volume by a snapstart operation, and the
number of plexes in a snapshot volume for snapshot and snapback operations. For a snapshot, there must be number SNAPDONE plexes
available in the original volume. For a snapback, there must be number snapshot plexes available in the snapshot volume (which
must also be in the same disk group as the original volume).
nraid5log= number
(alias: nraid5logs, raid5logs, nraidlog, nraidlogs, raidlogs)
Specifies the number of log plexes to create for a new RAID-5 volume (default value is 1). This attribute is used only with the
make operation.
nraid5stripe=[+|-]number
(alias: raid5stripes, nraid5column, nraidstripe, raidstripes, raidcolumns, nraidcolumn, raid5columns)
Specifies the number of stripe columns to use when creating a new RAID-5 volume (the default is to adjust the number to available
disks). This attribute is used only with make and relayout operations. For the relayout operation, the default is the same num-
ber of stripe columns the volume has. For a relayout, this value can be preceded by a + or a - to add or subtract columns.
nregionlog= number (alias: nregionlogs, regionlogs, ndrl)
Specifies the number of log subdisks to create for a new mirrored volume (default value 1). This attribute is used only with the
make operation, and only if logging is requested for the volume.
nstripe=[+|-]number
(alias: stripes, ncolumn, ncolumns, ncol, ncols, columns, cols)
Specifies the number of stripe columns to use when creating a new RAID-5 volume (with the make operation) or when creating a
striped plex (with the make, relayout, mirror, and snapstart operations). The usual default behavior is to adjust to the number
of available disks, but there are exceptions to this rule.
When creating an unmirrored striped volume, the default behavior is to adjust to half the number of available disks. This allows
for the subsequent addition of a mirror to the volume. (A volume that does not have data redundancy cannot recover from disk
failure.)
For relayout operations, the default behavior is to conserve the number of stripe columns in the volume. In such operations, the
value of number can be preceded by + or - to specify a number of columns that are to be added or subtracted.
nvol= number
(alias: nvols) Specifies the number of volumes to be created by the make operation. The volumes are named using the specified
volume name as a prefix with a number starting from 1 appended. If any volume names already exist in the same pool with the same
prefix and an appended number, numbering starts at the highest number found plus 1.
Note: This attribute is supported for operations on ISP volumes only.
probe_granularity= size
Specifies the granularity for the maxsize request. The default size value is 1 megabyte.
raid5_stripeunit= width
(alias: raid5_stwid, raid5_st_width, raid5_stwidth, raid_st_width, raid_stripeunitsize, raid5_stripeunitsize, raid5_stripeu-
nitwidth, raid_stwid, raid_stwidth, raid_stripeunit, raid_stripeunitwidth)
Specifies the stripe unit size to use when creating a new RAID-5 volume (default value is 16k (16 kilobytes)). This attribute is
used only with the make operation.
raid5loglen= length (alias: raidloglen)
Specifies the log length to use when adding the first log to a RAID-5 volume. The default is four times the full stripe width
(the stripe unit size times the number of stripe columns).
regionloglen= length (alias: drlloglen, drllen)
Specifies the log subdisk length to use when adding the first log subdisk to a mirrored volume. The default is chosen based on a
formula involving the volume length.
regionsz= size
Specifies the size of each region that is tracked by a bit in the maps within a version 20 DCO volume. The value of size must be
a power of 2 and be greater than or equal to 16k(16KB). The default value is 64k(64KB). The region size must also be no
greater than half the value of the voliomem_maxpool_sz tunable. Otherwise, only a limited set of instant snapshot operations are
permitted on the volume. For more information, see the vxsnap(1M) manual page.
Note: The region size can only be specified for version 20 DCOs. It cannot be specified for version 0 DCOs.
siteconsistent={on|off}
Controls whether a volume that is being created inherits the site-consistency attribute setting that is configured on the disk
group (see vxdg(1M)). This setting is persistent, and does not change when the setting on the disk group is changed.
If set to on, a volume that is being created must have a number of mirrors equal to or a multiple of the number of sites. If off
is specified, this requirement is removed.
By default, creating a site-consistent volume also creates an associated DCO volume, and enables Persistent FastResync on the
volume. This allows faster recovery of the volume during site reattachment.
Note: Site consistency is not supported for RAID-5 volumes.
spare=no|only|yes
Controls the use of spare disks when hot-relocation is performed.
If set to yes, spare disks are used. If necessary, free space is also used on disks that have been marked nohotuse=off. This is
the default behavior.
If set to only, relocation storage is allocated using only spare disks.
If set to no, spare disks are not used. Alternatively, do not mark any of your disks as spares and do not mark them as available
for use by hot relocation.
stripe= diskclass[,...]
Specifies that volumes should be striped across instances of a particular disk class. For example, stripe=target specifies that
volumes should be striped between SCSI target addresses. Each column can contain disks from any number of instances of the disk
class, but different columns cannot use disks from the same instance of the disk class.
stripe-mirror-col-trigger-pt= size
Specifies a size that triggers the creation of a stripe-mirror volume. If the size of the volume is greater than the size speci-
fied in this attribute, then a stripe-mirror volume is created.
stripe-mirror-col-split-trigger-pt= size
Specifies a size that triggers the creation of a stripe-mirror-sd volume. If the size of each column is greater than the size
specified in this attribute, then a stripe-mirror-sd volume is created.
stripe_stripeunit= width
(alias: stripe_stwid, stripe_stwidth, stripe_st_width, stripe_stripeunitsize, stripe_stripeunitwidth)
Specifies the stripe unit size to use when creating striped plexes to attach to a volume. When attaching a new plex, the default
is to use the same stripe unit size as any other striped plexes in the volume. If the volume does not already contain striped
plexes, the default value is 64k (64 kilobytes).
stripeunit= width
(alias: stwid, stripewidth, stwidth, st_width, stripe_width, stripeunitsize, stripeunitwidth)
Specifies the stripe unit size to use for either a RAID-5 volume or for striped plexes. stripeunit can be used to set the values
for both raid5_stripeunit and stripe_stripeunit.
tag= tagname[=[ tagvalue]]
Associates a tag name and optional tag value with a volume that is being created. Tag names and tag values are case-sensitive
character strings of up to 256 characters, consisting of letters, numbers, dashes (-), underscores (_) or periods (.). A tag
name should start with either a letter or an underscore.
The tag names "site", "udid" and "vdid" are reserved and should not be used. To avoid possible clashes with future product fea-
tures, it is recommended that tag names do not start with any of the following strings: "asl", "be", "isp", "nbu", "sf", "symc"
or "vx".
If not specified, a tag value is set to null.
More than one tag may be associated with a volume provided that each tag is uniquely named.
tmplen= size
Controls the size of the temporary volume that is used for add column, remove column and setstwidth operations. If not speci-
fied, the size of the temporary volume is based on the size of the volume that is being operated upon.
Note: The temporary volume is a 2-way mirror that requires at least two disks, and twice as much disk space as the size of the
temporary volume.
tmpsize= size
Specifies the size of the temporary storage used to perform a relayout operation.
tmpalloc= storage-spec[,storage-spec,...]
Specifies a set of storage specifications for the temporary storage required during a relayout operation. The format is the same
as for the alloc attribute (a comma-separated list of storage specifications).
type={cachevolume|data|snapshot}
Sets the type of a volume to data for a normal volume, snapshot for a volume that is being created to hold a full-sized instant
snapshot, or cache for a volume that is being created to hold the cache volume for use by space-optimized instant snapshots.
If no type is specified, data is assumed.
For the cachevolume type, a cache object is also created above the cache volume.
For the snapshot type, a DCO and DCO volume are also created for the volume.
Note: This attribute is supported for operations on ISP volumes only.
user= owning-user
Specifies the user ID for a new volume (default value is root). The user ID can be specified numerically or it can be a system
login name. This attribute is used only with the make operation.
user_template= ut1[,ut2, ...]
Specifies the list of user templates to be used with a make, maxsize, or transform operation.
Note: This attribute is supported for operations on ISP volumes only.
usetype= volume-usage-type
Specifies the usage type to use when creating a new volume (default value is raid5 for RAID-5 volumes; otherwise fsgens the
default). This attribute is only used with the make operation. The usage type can also be specified using the -U option.
volume_template= t1[,t2 ...]
Specifies a list of volume templates to be used with a make, maxsize, or transform operation.
See the Veritas Storage Foundation Intelligent Storage Provisioning Administrator's Guide for a list of the set of volume tem-
plates that are provided by Veritas Volume Manager.
Note: This attribute is supported for operations on ISP volumes only.
wantalloc= storage-spec[,storage-spec,...]
Specifies a set of desired storage specifications. This is useful in a defaults file to indicate desired storage specifications
that should be discarded if they fail to yield a reasonable set of allocations. The format is the same as for the alloc
attribute (a comma-separated list of storage specifications).
For example, a defaults file can name a specific controller type to use for allocations, if possible. When all disks on that type
of controller are full, other controllers are used.
wantmirror= diskclass[,diskclass,...]
Specifies a desired list of disk class mirroring specifications. This is useful in a defaults file to indicate a set of desired
mirroring constraints that can be dropped if they fail to yield a reasonable set of allocations.
For example, a defaults file can specify that volumes should be mirrored between disks on different controllers in the system.
The constraint is dropped if the set of volumes builds up in such a way that a new volume cannot be mirrored across controllers.
wantmirrorconfine= diskclass[,diskclass,...]
Specifies a list of disk classes for mirror confinement constraints. A single mirror is confined to (that is, allocated entirely
from) a group of disks belonging to a single disk class.
This is useful in a defaults file to indicate a set of mirror confinement constraints that can be dropped if they fail to yield a
reasonable set of allocations. For example, a defaults file can specify that a single mirror be confined to disks of the same
vendor:
wantmirrorconfine=vendor
If vxassist cannot allocate a mirror from disk devices of one vendor, this constraint is dropped and the mirror is allocated from
disk devices of other vendors.
wantstripe= diskclass[,diskclass,...]
Specifies a desired list of disk class stripping specifications. This is useful in a defaults file to indicate a set of desired
stripping constraints that can be dropped if they fail to yield a reasonable set of allocations.
For example, a defaults file can specify that volumes should be striped between disks on different controllers in the system.
The constraint is dropped if the set of volumes builds up in such a way that a new volume cannot be striped across controllers.
Layout Specifications
The layout attribute specifies a comma-separated list of simple parameters (with no arguments) that apply to vxassist operations.
Two new layouts were added in the 3.0 release of VxVM: stripe-mirror and concat-mirror. In previous releases, whenever mirroring was used,
the mirroring had to happen above striping or concatenation. Now there can be mirroring both above and below striping and concatenation.
Putting mirroring below striping mirrors each column of the stripe. If the stripe is large enough to have multiple subdisks per column,
each subdisk can be individually mirrored. A similar concatenated volume would also mirror each subdisk individually. These new layouts
enhance redundancy and reduce recovery time in case of an error. In a mirror-stripe layout, if a disk fails, the entire plex is detached,
thereby losing redundancy on the entire volume. When the disk is replaced, the entire plex must be brought up to date. Recovering the
entire plex can take a substantial amount of time. If a disk fails in a stripe-mirror layout, only the failing subdisk must be detached,
and only that portion of the volume loses redundancy. When the disk is replaced, only a portion of the volume needs to be recovered.
The new volume layouts are more complex than the older volume layouts. Because the advantages of recovery time and improved redundancy are
more important for larger volumes, it is best to continue using mirror-stripe and mirror-concat for most volumes and only use stripe-mirror
and concat-mirror for very large volumes.
You can specify layout=mirror-stripe or layout=stripe-mirror to implement the desired layout. If you specify layout=stripe,mirror or lay-
out=mirror,stripe, vxassist automatically determines the best layout for the volume. Unless there is a reason to implement a particular
layout, it is best to let vxassist create the layout for each volume. Because the advantages of the new layouts are related to the size of
the volume, vxassist creates the simplest configuration for smaller volumes and the more complex stripe-mirror for larger volumes.
The attributes stripe-mirror-col-trigger-pt and stripe-mirror-col-split-trigger-pt control the selection. They can be set in
/etc/default/vxassist. Volumes that are smaller than stripe-mirror-col-trigger-pt are created as mirror-stripe, and volumes that are
larger are created as stripe-mirror. If vxassist creates the stripe-mirror and the columns are larger than stripe-mirror-col-split-trig-
ger-pt, the individual subdisks are mirrored instead of mirroring the columns of the stripe. By default, both of these attributes are set
to one gigabyte.
The disk group must be created on a 3.0 or later release to use the new layouts, but older disk groups can be updated. See the vxdg
upgrade command for more information on upgrading disk groups.
Defined layout specifications are:
concat-mirror
Specifies that new volumes should be concatenated and mirrored. The mirroring is handled at each subdisk level. The attribute
stripe-mirror-col-split-trigger-pt is applied.
contig, nocontig
Disallows or allows (default) plexes, regular stripe columns, or RAID-5 stripe columns from using multiple regions of disk. If
contig is specified, then plexes and columns must be allocated from a single contiguous region of disk. If this is not possible,
the allocation fails. By default, vxassist tries to allocate space contiguously, but it can use multiple regions or multiple
disks if required.
dgalign_checking={round|strict}
Controls how vxassist handles attributes that are subject to disk group alignment restrictions. If set to strict, the volume
length and values of attributes must be integer multiples of the disk group alignment value. If set to round (default),
attribute values are rounded up as required.
diskalign, nodiskalign
Aligns (default for all volumes except layered volumes) or does not align subdisks on cylinder boundaries. When alignment is not
disabled, subdisks are created beginning on cylinder boundaries and are extended to match the end of a cylinder. Dirty region
log subdisks, however, are not cylinder aligned (they are usually only 2 or 3 blocks long). Instead, when creating log subdisks,
spaces are located from the available disks that could not be turned into regular subdisks because the spaces are not cylinder
aligned. For example, once one cylinder is used for a log subdisk, that cylinder cannot be used to create an aligned data (or
RAID-5 log) subdisk, so other log subdisks are created there until that cylinder fills up.
Note: vxassist always uses the disk group alignment value for EFI disks. If the value of the disk group alignment is greater
than 1, specifying diskalign for EFI disks results in an error. The disk and cylinder alignment values for EFI disks are always
set to 1. See vxdg(1M) for more information.
The diskalign attribute is not supported for layered volumes (concat-mirror and stripe-mirror).
grow, nogrow
Allows a volume to grow during a relayout operation.
log, nolog
Creates (or does not create) dirty region logs (for mirrored volumes) or log plexes (for RAID-5 volumes) when creating a new vol-
ume. This attribute can be specified independently for mirrored and RAID-5 volumes with the raid5log and regionlog layout speci-
fications. The current implementation does not support the creation of DCM logs in the layout specification.
mirror, nomirror
Specifies that new volumes should be mirrored or unmirrored (default) respectively. For mirror, the attribute stripe-mirror-col-
split-trigger-pt is applied, and the attribute stripe-mirror-col-trigger-pt is ignored.
mirror-concat
Specifies that new volumes should be mirrored. The mirroring is done at the volume level. The attributes stripe-mirror-col-
trigger-pt and stripe-mirror-col-split-trigger-pt are ignored with this layout.
mirror-stripe
Specifies that new volumes should be mirrored and striped. The mirroring is done at the volume level. The attributes stripe-mir-
ror-col-trigger-pt and stripe-mirror-col-split-trigger-pt are ignored with this layout.
raid5 Specifies that new volumes should be RAID-5.
raid5log, noraid5log
Creates (default) or does not create log plexes for RAID-5 volumes.
regionlog, noregionlog
Creates or does not create (default) dirty-region log subdisks for mirrored volumes.
shrink, noshrink
Allows or disallows shrinking of a volume during a relayout operation.
span, nospan
Allows (default) or disallows plexes, regular stripe columns, or RAID-5 stripe columns from spanning multiple disks. If nospan is
indicated, then plexes or columns can be formed from multiple regions of the same disk, but cannot be formed from more than one
disk.
stripe, nostripe
Specifies that new plexes should be striped or unstriped, respectively. When creating a new volume, the default is nostripe. When
adding a new plex to an existing volume, the default is stripe if the volume already has one or more striped plexes, and nostripe
in other cases. For stripe (when combined with mirror), the attributes stripe-mirror-col-trigger-pt and stripe-mirror-col-split-
trigger-pt are applied.
stripe-mirror
Specifies that new volumes should be striped and mirrored. The mirroring is handled at each column level or subdisk level depend-
ing on the attribute stripe-mirror-col-split-trigger-pt.
stripe-mirror-col
Specifies that new volumes should be striped and mirrored. The mirroring is handled at each column level. The attributes stripe-
mirror-col-trigger-pt and stripe-mirror-col-split-trigger-pt are ignored with this layout.
stripe-mirror-sd
Specifies that new volumes should be striped and mirrored. The mirroring is handled at each subdisk level.
Ordered Allocation
If the -o ordered option is specified when creating a volume, vxassist uses the specified storage in the following order:
1. Concatenate disks.
2. Form columns.
3. Form mirrors.
For example, the following command creates a mirrored-stripe volume with 3 columns and 2 mirrors on 6 disks:
vxassist -o ordered make mirstrvol 10g layout=mirror-stripe
nstripe=3 disk01 disk02 disk03 disk04 disk05 disk06
This command places columns 1, 2 and 3 of the first mirror on disk01, disk02 and disk03 respectively, and columns 1, 2 and 3 of the second
mirror on disk04, disk05 and disk06 respectively.
For layered volumes, the same rules are used to allocate storage as for non-layered volumes. For example, the following command creates a
striped-mirror volume with 2 mirrored columns:
vxassist -o ordered make strmirvol 10g layout=stripe-mirror
nstripe=2 disk01 disk02 disk03 disk04
This command mirrors column 1 across disk01 and disk03, and column 2 across disk02 and disk04.
The col_switch attribute can additionally be used to specify how space on the disks is to be concatenated into columns. For example, the
following command creates a mirrored-stripe volume with 2 columns:
vxassist -o ordered make strmir2vol 10g layout=mirror-stripe
nstripe=2 col_switch=3g,2g disk01 disk02 disk03 disk04
disk05 disk06 disk07 disk08
This command allocates 3 gigabytes from disk01 and 2 gigabytes from disk02 to column 1, and 3 gigabytes from disk03 and 2 gigabytes from
disk04 to column 2. The mirrors of these columns are then similarly formed from disks disk05 through disk08.
Other storage specification classes for controllers, enclosures, targets and trays can be used with ordered allocation. For example, the
following command creates a 3-column mirrored-stripe volume between specified controllers:
vxassist -o ordered make mirstr2vol 10g layout=mirror-stripe
nstripe=3 ctlr:c1 ctlr:c2 ctlr:c3 ctlr:c4 ctlr:c5 ctlr:c6
This command allocates space for column 1 from disks on controller c1, for column 2 from disks on controller c2, and so on.
Allocator Rules
The storage allocation language in ISP supports the following rules:
affinity Expresses attraction between VxVM objects. Objects that conform to this rule share as many attribute values as possible.
confineto Depending on the scope in which the rule is used, confines a volume, mirror, column or log to a specific set of LUNs.
confineto expressions may be used with the allof, anyof, eachof, noneof and oneof operators.
The default operator for merging confineto expressions is eachof.
exclude Depending on the scope in which the rule is used, excludes a set of LUNs from allocation to a volume, mirror, column or log.
exclude expressions may be used with the allof, eachof and noneof operators.
The noneof operator can be used to forcibly include sets of LUNs in the allocation.
The default operator for merging exclude expressions is eachof.
multipath Specifies how tolerant a VxVM object is to the failure of a number of specified components. The rule defines how many paths a
VxVM object should have available through each component.
Note: Expressions involving multipath do not use operators to combine multiple arguments.
parity Specifies whether redundancy should be based on parity. Parity-based redundancy is typically implemented using a RAID-5 layout
in hardware or using software.
select Depending on the scope in which the rule is used, confines a volume, mirror, column or log to a specific set of LUNs. specifies
storage that can be allocated to create a volume, mirror, column or log.
select expressions may be used with the allof, anyof, eachof, noneof and oneof operators.
The default operator for merging select expressions is anyof.
separateby
Defines how mirrors are separated in a volume. A separateby expression is typically used to place mirrors in different failure
domains for greater reliability.
striped Specifies whether a volume or mirror is to be striped. As striping can be implemented in hardware as well as in software, a
value of true does not imply that the number of columns is greater than one.
strong separateby
A more restrictive form of the separateby rule, that does not permit any sharing of attributes for the storage that is assigned
to VxVM objects
Simplified Rule Syntax
For convenience, rules may be expressed in the following simplified form on the command line:
rulename= attribute_name[= value][, ...]
as shown in the following examples:
confineto=VendorName=EMC,Room=Room1,Building
select=Room=Room1,Room=Room2,Building
exclude=VendorName=EMC,VendorName=Hitachi
affinity=Enclosure
separateby=Controller
strong separateby=Spindles
which are equivalent to these rule expressions:
confineto eachof("VendorName"="EMC","Room"="Room1","Building")
select anyof("Room"="Room1","Room"="Room2","Building")
exclude allof("VendorName"="EMC","VendorName"="Hitachi")
affinity "Enclosure"
separateby "Controller"
strong separateby "Spindles"
See the Veritas Storage Foundation Intelligent Storage Provisioning Administrator's Guide for details of the syntax of rule expressions.
OPERATORS
allof Selects available storage that matches the union of all of the operands.
anyof Selects available storage that matches any of the operands in the order that they are listed. The first match is chosen.
eachof Selects available storage that matches the intersection of the operands.
noneof Does not select storage that matches any of the operands.
oneof Selects available storage that matches one and only one of the operands. The first match is chosen.
See the Veritas Storage Foundation Intelligent Storage Provisioning Administrator's Guide for more information about these operators.
Operations on Multiple Volumes
Note: Operations on multiple volumes are only supported for ISP volumes.
The make, grow and shrink operations can usually only be performed on a single volume that is specified on the command line. The migrate
operation can be performed on multiple volumes that are specified on the command line, but the same rules are applied to each volume, and
only a single destination storage pool may be used. This limitation may be overcome by specifying the -M option with these operations. The
command then reads multiple volume definitions from the standard input until the end of file is encountered. Input can be redirected from
a definitions file or from a here document.
The -M option can also be used to add mirrors to (mirror), or to remove mirrors from (remove mirror) multiple volumes in a single opera-
tion.
The syntax of the definitions for creating multiple volumes with make is shown here:
volumegroup {
[diskgroup "dgname"]
[rules { volume-group-rules } ]
volume "name" length {
[cachevolume "cachevol"]
[capability 'capability[(name=value[, ...])],capability ...]']
[comment "comment"]
[dcologlen length]
[dm dm1,[dm2, ...]]
[drl on|off|true|false|yes|no|sequential]
[excl on|off|true|false|yes|no]
[fmr on|off|true|false|yes|no]
[fstype file-system-type]
[group "group"]
[init active|none|zero]
[iodelay delay]
[iosize size]
[layout "type"]
[max_ncolumn number]
[max_nraid5column number]
[min_ncolumn number]
[min_nraid5column number]
[mode mode]
[nvol number]
[pool "poolname"]
[raid5_stripeunit width]
[raid5loglen length]
[regionsize size]
[rules { volume-rules } ]
[spare yes|no|only]
[stripe_stripeunit width]
[tag "volume_tag"]
[tasktag "tag"]
[type cachevolume|data|snapshot]
[user "user"]
[user_template "ut1[,ut2 ...]"]
[usetype volume-usage-type]
[volume_template "vt1[,vt2 ...]"]
[vxvmtaskid taskid]
}
[volume "name2" length2 {
...
}]
};
[volumegroup {
...
};]
Each volume group (volumegroup) definition contains the rules and volume definitions for the volumes that are to be created for a disk
group.
For the migrate operation, the specification syntax is:
diskgroup "dgname"
volume "volumename1" {
pool "pool_name1"
rules { volume1_rules }
};
volume "volumename2" {
pool "pool_name2"
rules { volume2_rules }
};
...
For operations to grow or shrink multiple volumes, the syntax of each line in the input is:
diskgroup dgname volume volname length
The following example adds two mirrors to three volumes at the site s1 in a single operation:
vxassist -g mydg -M mirror v1 v2 v3 site:s1 nmir=2
The following example removes one mirror from three volumes at the site s2 in a single operation:
vxassist -g mydg -M remove mirror v1 v2 v3 site:s2
ISP EXAMPLES
Maximum Volume Size
Find out the maximum size of a mirrored volume that can be created in the storage pool mypool within the disk group mydg using the avail-
able free storage:
vxassist -g mydg -P mypool maxsize capability='DataMirroring'
Volume Creation
Create a 100-megabyte concatenated volume with 2 mirrors in the default disk group, and which is made immediately active:
vxassist make -o intent vol1 100m rules='mirror 2' init=active
Create a 20-gigabyte striped volume with 4 stripes and its contents initialized to all zeros:
vxassist -g mydg make vol2 20g rules='stripe 4' init=zero
Create a 500-megabyte mirrored-stripe volume which is not initialized:
vxassist -g mydg make vol3 500m init=none
rules='mirror 2{stripe 3}'
Using the DataStripeMirror capability,
create a 30-gigabyte striped-mirror volume which is immediately active:
vxassist -g mydg make vol4 30g
capability='DataStripeMirror(ncols=3,nmirs=2)'
init=active
Create a 500-megabyte mirrored volume, relvol, using
the volume template DataMirroring.
vxassist -g mydg make relvol 500m volume_template=DataMirroring
Create a 10-gigabyte 4-mirror volume, perfvol, on hardware-striped EMC storage that is in the same location:
vxassist -g mydg make perfvol 10g
capability='DataMirroring(nmirs=4),PrefabricatedStriping'
rules='confineto allof("Room","Vendor"="EMC")'
Multiple Volume Creation
Create a 1-gigabyte contiguous volume, tvol1, and a 10-gigabyte mirrored volume, tvol2:
vxassist -M make <<!!
volumegroup {
diskgroup "tvdg"
volume "tvol1" 1g {
layout "contig"
}
volume "testvol2" 10g {
init active
capability 'DataMirroring(nmirs=3)'
}
};
!!
Mirror Addition and Removal
Add two mirrors to the volume myrelvol:
vxassist -g mydg mirror myrelvol nmirror=2
Add a mirror to the volume myvol2 using disk mydg10
for storage:
vxassist -g mydg mirror myvol2 dm:mydg10
Remove the two mirrors from volume myvol3 with
plexes named plex01 and plex02:
vxassist -g mydg remove mirror testvol3 nmirror=2
plexnames=plex01,plex02
Maximum Growable Volume Size
Find out the maximum size to which the volume relvol can be grown:
vxassist -g mydg maxgrow relvol
Growing and Shrinking Volumes
Grow the volume pervol by 25%:
vxassist -g mydg growby pervol 25%
Shrink the volume myvol by 100MB:
vxassist -g mydg shrinkby myvol 100m
Growing and Shrinking Multiple Volumes
Grow several volumes in varying disk groups by different amounts:
vxassist -M growby <<!!
diskgroup ttdg volume vol1 100m
diskgroup ttdg volume vol2 200m
diskgroup mydg volume myvol3 50%
!!
Shrink several volumes in different disk groups by varying amounts:
vxassist -M shrinkto <<!!
diskgroup ttdg volume vol1 1g
diskgroup mydg volume myvol4 90%
!!
Log Addition and Removal
Add a DCO log to the volume tvol1:
vxassist -g ttdg addlog tvol1 logtype=dco
Remove the DCO log from the volume tvol1:
vxassist -g ttdg remove log tvol1 logtype=dco
Growing a Log
Grow the DCO volume associated with the volume myvol2 by 100%:
vxassist -g mydg growlogby myvol2 100% logtype=dco
Volume Removal
Delete the volume vol2:
vxassist -g mydg remove volume vol2
FILES
/etc/default/allocator System default settings file for ISP volumes.
/etc/default/vxassist System default settings file for non-ISP volumes.
EXIT CODES
The vxassist utility exits with a non-zero status if the attempted operation fails. A non-zero exit code is not a complete indicator of the
problems encountered, but rather denotes the first condition that prevented further execution of the utility.
See vxintro(1M) for a list of standard exit codes.
SEE ALSO
chmod(1), fstyp(1M), sync(1M), vxedit(1M), vxintro(1M), vxmake(1M), vxmend(1M), vxplex(1M), vxrelayout(1M), vxresize(1M), vxsd(1M), vxs-
nap(1M), vxtask(1M), vxvol(1M), vxvoladm(1M)
VxVM 5.0.31.1 24 Mar 2008 vxassist(1M)