LVM(8)                                                        System Manager's Manual                                                       LVM(8)

NAME

       lvm - LVM2 tools

SYNOPSIS

       lvm [command | file]

DESCRIPTION

       lvm provides the command-line tools for LVM2.  A separate manual page describes each command in detail.

       If  lvm  is  invoked with no arguments it presents a readline prompt (assuming it was compiled with readline support).  LVM commands may be
       entered interactively at this prompt with readline facilities including history and command name and option  completion.   Refer  to  read-
       line(3) for details.

       If  lvm  is  invoked with argv[0] set to the name of a specific LVM command (for example by using a hard or soft link) it acts as that com-
       mand.

       On invocation, lvm requires that only the standard file descriptors stdin, stdout and stderr are available.  If others are found, they  get
       closed and messages are issued warning about the leak.

       Where  commands  take VG or LV names as arguments, the full path name is optional.  An LV called "lvol0" in a VG called "vg0" can be speci-
       fied as "vg0/lvol0".  Where a list of VGs is required but is left empty, a list of all VGs will be substituted.  Where a  list  of  LVs  is
       required  but  a  VG is given, a list of all the LVs in that VG will be substituted.  So "lvdisplay vg0" will display all the LVs in "vg0".
       Tags can also be used - see addtag below.

       One advantage of using the built-in shell is that configuration information gets cached internally between commands.

       A file containing a simple script with one command per line can also be given on the  command  line.   The  script  can  also  be  executed
       directly if the first line is #! followed by the absolute path of lvm.

BUILT-IN COMMANDS
       The following commands are built into lvm without links normally being created in the filesystem for them.

       dumpconfig -- Display the configuration information after
              loading lvm.conf (5) and any other configuration files.

       formats -- Display recognised metadata formats.

       help -- Display the help text.

       pvdata -- Not implemented in LVM2.

       segtypes -- Display recognised logical volume segment types.

       version -- Display version information.

COMMANDS

       The following commands implement the core LVM functionality.

       pvchange -- Change attributes of a physical volume.

       pvck -- Check physical volume metadata.

       pvcreate -- Initialize a disk or partition for use by LVM.

       pvdisplay -- Display attributes of a physical volume.

       pvmove -- Move physical extents.

       pvremove -- Remove a physical volume.

       pvresize -- Resize a disk or partition in use by LVM2.

       pvs -- Report information about physical volumes.

       pvscan -- Scan all disks for physical volumes.

       vgcfgbackup -- Backup volume group descriptor area.

       vgcfgrestore -- Restore volume group descriptor area.

       vgchange -- Change attributes of a volume group.

       vgck -- Check volume group metadata.

       vgconvert -- Convert volume group metadata format.

       vgcreate -- Create a volume group.

       vgdisplay -- Display attributes of volume groups.

       vgexport -- Make volume groups unknown to the system.

       vgextend -- Add physical volumes to a volume group.

       vgimport -- Make exported volume groups known to the system.

       vgimportclone -- Import and rename duplicated volume group (e.g. a hardware snapshot).

       vgmerge -- Merge two volume groups.

       vgmknodes -- Recreate volume group directory and logical volume special files

       vgreduce -- Reduce a volume group by removing one or more physical volumes.

       vgremove -- Remove a volume group.

       vgrename -- Rename a volume group.

       vgs -- Report information about volume groups.

       vgscan -- Scan all disks for volume groups and rebuild caches.

       vgsplit -- Split a volume group into two, moving any logical volumes from one volume group to another by moving entire physical volumes.

       lvchange -- Change attributes of a logical volume.

       lvconvert -- Convert a logical volume from linear to mirror or snapshot.

       lvcreate -- Create a logical volume in an existing volume group.

       lvdisplay -- Display attributes of a logical volume.

       lvextend -- Extend the size of a logical volume.

       lvmchange -- Change attributes of the logical volume manager.

       lvmdiskscan -- Scan for all devices visible to LVM2.

       lvmdump -- Create lvm2 information dumps for diagnostic purposes.

       lvreduce -- Reduce the size of a logical volume.

       lvremove -- Remove a logical volume.

       lvrename -- Rename a logical volume.

       lvresize -- Resize a logical volume.

       lvs -- Report information about logical volumes.

       lvscan -- Scan (all disks) for logical volumes.

       The following commands are not implemented in LVM2 but might be in the future: lvmsadc, lvmsar, pvdata.

OPTIONS

       The following options are available for many of the commands.  They are implemented generically and documented here rather than repeated on
       individual manual pages.

       -h | --help -- Display the help text.

       --version -- Display version information.

       -v | --verbose -- Set verbose level.
              Repeat from 1 to 3 times to increase the detail of messages sent to stdout and stderr.  Overrides config file setting.

       -d | --debug -- Set debug level.
              Repeat from 1 to 6 times to increase the detail of messages sent to the log file and/or syslog (if  configured).   Overrides  config
              file setting.

       --quiet -- Suppress output and log messages.
              Overrides -d and -v.

       -t | --test -- Run in test mode.
              Commands  will not update metadata.  This is implemented by disabling all metadata writing but nevertheless returning success to the
              calling function.  This may lead to unusual error messages in multi-stage operations if a tool relies on reading  back  metadata  it
              believes has changed but hasn't.

       --driverloaded { y | n }
              Whether or not the device-mapper kernel driver is loaded.  If you set this to n, no attempt will be made to contact the driver.

       -A | --autobackup { y | n }
              Whether  or  not  to  metadata should be backed up automatically after a change.  You are strongly advised not to disable this!  See
              vgcfgbackup (8).

       -P | --partial
              When set, the tools will do their best to provide access to volume groups that are only partially available (one  or  more  physical
              volumes belonging to the volume group are missing from the system).  Where part of a logical volume is missing, /dev/ioerror will be
              substituted, and you could use dmsetup (8) to set this up to return I/O errors when accessed, or create it as a large  block  device
              of  nulls.   Metadata  may  not  be  changed with this option. To insert a replacement physical volume of the same or large size use
              pvcreate -u to set the uuid to match the original followed by vgcfgrestore (8).

       -M | --metadatatype type
              Specifies which type of on-disk metadata to use, such as lvm1 or lvm2, which can be abbreviated to 1 or 2 respectively.  The default
              (lvm2) can be changed by setting format in the global section of the config file.

       --ignorelockingfailure
              This  lets  you  proceed  with read-only metadata operations such as lvchange -ay and vgchange -ay even if the locking module fails.
              One use for this is in a system init script if the lock directory is mounted read-only when the script runs.

       --addtag tag
              Add the tag tag to a PV, VG or LV.  Supply this argument multiple times to add more than one tag at once.  A tag is a word that  can
              be  used to group LVM2 objects of the same type together.  Tags can be given on the command line in place of PV, VG or LV arguments.
              Tags should be prefixed with @ to avoid ambiguity.  Each tag is expanded by replacing it with all objects possessing that tag  which
              are  of  the type expected by its position on the command line.  PVs can only possess tags while they are part of a Volume Group: PV
              tags are discarded if the PV is removed from the VG.  As an example, you could tag some LVs as database and others as  userdata  and
              then  activate  the database ones with lvchange -ay @database.  Objects can possess multiple tags simultaneously.  Only the new LVM2
              metadata format supports tagging: objects using the LVM1 metadata format cannot be tagged because the on-disk format does  not  sup-
              port  it.   Snapshots cannot be tagged.  Characters allowed in tags are: A-Z a-z 0-9 _ + . - and as of version 2.02.78 the following
              characters are also accepted: / = ! : # &

       --deltag tag
              Delete the tag tag from a PV, VG or LV, if it's present.  Supply this argument multiple times to remove more than one tag at once.

       --alloc AllocationPolicy
              The allocation policy to use: contiguous, cling, normal, anywhere or inherit.  When a command needs  to  allocate  physical  extents
              from  the  volume group, the allocation policy controls how they are chosen.  Each volume group and logical volume has an allocation
              policy.  The default for a volume group is normal which applies common-sense rules such as not placing parallel stripes on the  same
              physical volume.  The default for a logical volume is inherit which applies the same policy as for the volume group.  These policies
              can be changed using lvchange (8) and vgchange (8) or over-ridden on the command line of any command that performs allocation.   The
              contiguous policy requires that new extents be placed adjacent to existing extents.  The cling policy places new extents on the same
              physical volume as existing extents in the same stripe of the Logical Volume.  If there are sufficient free extents  to  satisfy  an
              allocation  request but normal doesn't use them, anywhere will - even if that reduces performance by placing two stripes on the same
              physical volume.

              N.B. The policies described above are not implemented fully yet.  In particular, contiguous free space cannot be broken up  to  sat-
              isfy allocation attempts.

ENVIRONMENT VARIABLES

       LVM_SYSTEM_DIR
              Directory containing lvm.conf and other LVM system files.  Defaults to "/etc/lvm".

       HOME   Directory containing .lvm_history if the internal readline shell is invoked.

       LVM_VG_NAME
              The volume group name that is assumed for any reference to a logical volume that doesn't specify a path.  Not set by default.

VALID NAMES

       The following characters are valid for VG and LV names: a-z A-Z 0-9 + _ . -

       VG  and LV names cannot begin with a hyphen.  There are also various reserved names that are used internally by lvm that can not be used as
       LV or VG names.  A VG cannot be called anything that exists in /dev/ at the time of creation, nor can it be called '.' or '..'.  A LV  can-
       not  be  called  '.'  '..'  'snapshot'  or  'pvmove'. The LV name may also not contain the strings '_mlog', '_mimage', '_rimage', '_tdata',
       '_tmeta'.

DIAGNOSTICS

       All tools return a status code of zero on success or non-zero on failure.

FILES

       /etc/lvm/lvm.conf
       $HOME/.lvm_history

SEE ALSO

       clvmd(8), lvchange(8), lvcreate(8), lvdisplay(8), lvextend(8), lvmchange(8), lvmdiskscan(8), lvreduce(8), lvremove(8),  lvrename(8),  lvre-
       size(8),  lvs(8),  lvscan(8),  pvchange(8),  pvck(8), pvcreate(8), pvdisplay(8), pvmove(8), pvremove(8), pvs(8), pvscan(8), vgcfgbackup(8),
       vgchange(8), vgck(8), vgconvert(8), vgcreate(8), vgdisplay(8), vgextend(8), vgimport(8), vgimportclone(8), vgmerge(8), vgmknodes(8),  vgre-
       duce(8), vgremove(8), vgrename(8), vgs(8), vgscan(8), vgsplit(8), readline(3), lvm.conf(5)

Sistina Software UK                                      LVM TOOLS 2.02.95(2) (2012-03-06)                                                  LVM(8)