metattach(1M)                                             System Administration Commands                                             metattach(1M)

NAME

       metattach, metadetach - attach or detach a metadevice

SYNOPSIS

       /usr/sbin/metattach [-h]

       /usr/sbin/metattach [-s setname] mirror [metadevice]

       /usr/sbin/metattach [-s setname] [-i interlace] concat/stripe component...

       /usr/sbin/metattach [-s setname] RAID component...

       /usr/sbin/metattach [-s setname] [-A alignment] softpart size | all

       /usr/sbin/metadetach [-s setname] [-f] mirror submirror

       /usr/sbin/metadetach [-s setname] [-f] trans

DESCRIPTION

       metattach  adds  submirrors  to a mirror, grows metadevices, or grows soft partitions. Growing metadevices can be done without interrupting
       service. To grow the size of a mirror or trans, the slices must be added to the submirrors or to the master devices.

       Solaris Volume Manager supports storage devices and logical volumes greater than 1 terabyte (TB) when a system runs a 64-bit  Solaris  ker-
       nel.  Support  for large volumes is automatic. If a device greater than 1 TB is created, Solaris Volume Manager configures it appropriately
       and without user intervention.

       If a system with large volumes is rebooted under a 32-bit Solaris kernel, the large volumes are visible through metastat output. Large vol-
       umes  cannot  be  accessed,  modified or deleted, and no new large volumes can be created. Any volumes or file systems on a large volume in
       this situation are also unavailable. If a system with large volumes is rebooted under a version of Solaris prior  to  the  Solaris  9  4/03
       release,  Solaris Volume Manager does not start. You must remove all large volumes before Solaris Volume Manager runs under an earlier ver-
       sion of the Solaris Operating System.

       Solaris Volume Manager supports one-to-four-way mirrors. You can only attach a metadevice to a mirror if there are three or  fewer  submir-
       rors  beneath  the mirror. Once a new metadevice is attached to a mirror, metattach automatically starts a resync operation to the new sub-
       mirror.

       metadetach detaches submirrors from mirrors and logging devices from trans metadevices.

       When a submirror is detached from a mirror, it is no longer part of the mirror, thus reads and writes to and from that metadevice by way of
       the mirror are no longer performed through the mirror. Detaching the only existing submirror is not allowed. Detaching a submirror that has
       slices reported as needing maintenance (by metastat) is not allowed unless the -f (force) flag is used.

       metadetach also detaches the logging device from a trans. This step is necessary before you can clear the trans volume.  Trans  metadevices
       have  been  replaced  by UFS logging. Existing trans devices are not logging. They pass data directly through to the underlying device. See
       mount_ufs(1M) for more information about UFS logging.

       Detaching the logging device from a busy trans device is not allowed unless the -f (force) flag is used. Even so, the logging device is not
       actually detached until the trans is idle. The trans is in the Detaching state (metastat) until the logging device is detached.

OPTIONS

       Root privileges are required for all of the following options except -h.

       The following options are supported:

       -A alignment

           Set  the value of the soft partition extent alignment. Use this option when it is important specify a starting offset for the soft par-
           tition. It preserves the data alignment between the metadevice address space and the address space of the underlying physical device.

           For example, a hardware device that does checksumming should not have its I/O requests divided by Solaris Volume Manager. In this case,
           use  a  value from the hardware configuration as the value for the alignment. When using this option in conjunction with a software I/O
           load, the alignment value corresponds to the I/O load of the application. This  prevents  I/O  from  being  divided  unnecessarily  and
           affecting performance.

       -f

           Force  the  detaching of metadevices that have components that need maintenance or are busy. You can use this option only when a mirror
           is in a maintenance state that can be fixed with metareplace(1M). If the mirror is in a maintenance state that can only be  fixed  with
           metasync(1M)  (as  shown by the output of metastat(1M)), metadetach -f has no effect, because the mirrors must be resynchronized before
           one of them can be detached.

       -h

           Display a usage message.

       -i interlace

           Specify the interlace value for stripes, where size is a specified value followed by either k for kilobytes, m for megabytes, or b  for
           blocks.  The  units can be either uppercase or lowercase. If size is not specified, the size defaults to the interlace size of the last
           stripe of the metadevice. When an interlace size change is made on a stripe, it is carried forward on all stripes that follow.

       -s setname

           Specify the name of the diskset on which the metattach command or the metadetach command works.. Using the -s option causes the command
           to  perform  its  administrative function within the specified diskset. Without this option, the command performs its function on local
           metadevices.

OPERANDS

       The following operands are supported:

       component

           The logical name for the physical slice (partition) on a disk drive, such as  /dev/dsk/c0t0d0s2,  being  added  to  the  concatenation,
           stripe, concatenation of stripes, or RAID5 metadevice.

       concat/stripe

           The metadevice name of the concatenation, stripe, or concatenation of stripes.

       log

           The metadevice name of the logging device to be attached to the trans metadevice.

       metadevice

           The metadevice name to be attached to the mirror as a submirror. This metadevice must have been previously created by the metainit com-
           mand.

       mirror

           The name of the mirror.

       RAID

           The metadevice name of the RAID5 metadevice.

       size | all

           The amount of space to add to the soft partition in K or k for kilobytes, M or m for megabytes, G or g for gigabytes, T or t  for  ter-
           abytes,  and B or b for blocks (sectors). All values represent powers of 2, and upper and lower case options are equivalent. Only inte-
           ger values are permitted. The literal all specifies that the soft partition should grow to occupy all available space on the underlying
           volume.

       softpart

           The metadevice name of the existing soft partition.

       submirror

           The metadevice name of the submirror to be detached from the mirror.

       trans

           The metadevice name of the trans metadevice (not the master or logging device).

EXAMPLES

       Example 1: Concatenating a New Slice to a Metadevice

       This  example concatenates a single new slice to an existing metadevice, d8. Afterwards, you would use the growfs(1M) command to expand the
       file system.

       # metattach d8 /dev/dsk/c0t1d0s2

       Example 2: Detaching Logging Device from Trans Metadevice

       This example detaches the logging device from a trans metadevice d9. Notice that you do not have to specify the logging device  itself,  as
       there can only be one.

       # metadetach d9

       Example 3: Expanding a RAID5 Metadevice

       This example expands a RAID5 metadevice, d45, by attaching another slice.

       # metattach d45 /dev/dsk/c3t0d0s2

       When you add additional slices to a RAID5 metadevice, the additional space is devoted to data. No new parity blocks are allocated. The data
       on the added slices is, however, included in the overall parity calculations, so it is protected against single-device failure.

       Example 4: Expanding a Soft Partition

       The following example expands a soft partition, d42, attaching all space available on the underlying device.

       # metattach d42 all

       When you add additional space to a soft partition, the additional space is taken from any available space on the slice  and  might  not  be
       contiguous with the existing soft partition.

       Example 5: Adding Space to Two-Way Mirror

       This example adds space to a two-way mirror by adding a slice to each submirror. Afterwards, you would use the growfs(1M) command to expand
       the file system.

       # metattach d9 /dev/dsk/c0t2d0s5
       # metattach d10 /dev/dsk/c0t3d0s5

       This example tells the mirror to grow to the size of the underlying devices

       # metattach d11

       This example increases the size of the UFS on the device so the space can be used.

       # growfs /dev/md/dsk/d11

       Example 6: Detaching a Submirror from a Mirror

       This example detaches a submirror, d2, from a mirror, d4.

       # metadetach d4 d2

       Example 7: Adding Four Slices to Metadevice

       This example adds four slices to an existing metadevice, d9. Afterwards, you would use the growfs(1M) command to expand the file system.

       # metattach d9 /dev/dsk/c0t1d0s2 /dev/dsk/c0t2d0s2      /dev/dsk/c0t3d0s2 /dev/dsk/c0t4d0s2

       Example 8: Setting the Value of the Soft Partition Extent Alignment

       This example shows how to set the alignment of the soft partition to 1mb when the soft partition is expanded.

       # metattach -s red -A 2m d13 1m

EXIT STATUS

       The following exit values are returned:

       0        Successful completion.

       >0       An error occurred.

ATTRIBUTES

       See attributes(5) for descriptions of the following attributes:

       +-----------------------------+-----------------------------+
       |      ATTRIBUTE TYPE         |      ATTRIBUTE VALUE        |
       +-----------------------------+-----------------------------+
       |Availability                 |SUNWmdu                      |
       +-----------------------------+-----------------------------+

SEE ALSO

       mdmonitord(1M), metaclear(1M), metadb(1M),  metahs(1M),  metainit(1M),  metaoffline(1M),  metaonline(1M),  metaparam(1M),  metarecover(1M),
       metarename(1M),  metareplace(1M),  metaroot(1M),  metaset(1M),  metassist(1M), metastat(1M), metasync(1M), md.tab(4), md.cf(4), mddb.cf(4),
       md.tab(4), attributes(5), md(7D)

       Solaris Volume Manager Administration Guide

WARNINGS

       This section provides information regarding warnings for devices greater than 1 TB and for multi-way mirrors.

   Devices and Volumes Greater Than 1 TB
       Do not create large (>1 TB) volumes if you expect to run the Solaris Operating System with a 32-bit kernel or if you expect to use  a  ver-
       sion of the Solaris Operating System prior to Solaris 9 4/03.

   Multi-Way Mirrors
       When a submirror is detached from its mirror, the data on the metadevice might not be the same as the data that existed on the mirror prior
       to running metadetach. In particular, if the -f option was needed, the metadevice and mirror probably do not contain the same data.

NOTES

       Trans metadevices have been replaced by UFS logging. Existing trans devices are not logging. They pass data directly through to the  under-
       lying device. See mount_ufs(1M) for more information about UFS logging.

SunOS 5.10                                                          20 Sep 2004                                                      metattach(1M)