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 a64-bit Solaris kernel. 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 metas-
tat output. Large volumes 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 Managerruns under an earlier version of the Solaris Operating Sys-
tem.SunOS 5.11 Last change: 20 Jun 2006 1
System Administration Commands metattach(1M)
Solaris Volume Manager supports one-to-four-way mirrors. You
can only attach a metadevice to a mirror if there are threeor fewer submirrors beneath the mirror. Once a new metadev-
ice is attached to a mirror, metattach automatically starts
a resync operation to the new submirror.metadetach detaches submirrors from mirrors and logging dev-
ices 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 unlessthe -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 datadirectly 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 notallowed 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 followingoptions except -h.
The following options are supported:-A alignment Set the value of the soft partition extent
alignment. Use this option when it is impor-
tant specify a starting offset for the soft partition. 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 doeschecksumming should not have its I/O requests divided by Solaris Volume Manager.
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System Administration Commands metattach(1M)
In this case, use a value from the hardwareconfiguration as the value for the align-
ment. When using this option in conjunctionwith 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 perfor-
mance.-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 theoutput 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, orb for blocks. The units can be either upper-
case 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 com-
mand 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 asSunOS 5.11 Last change: 20 Jun 2006 3
System Administration Commands metattach(1M)
/dev/dsk/c0t0d0s2, being added to the con-
catenation, 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 command. mirror The name of the mirror.RAID The metadevice name of the RAID5 metadev-
ice.size | all The amount of space to add to the soft par-
tition in K or k for kilobytes, M or m for megabytes, G or g for gigabytes, T or t for terabytes, and B or b for blocks (sectors). All values represent powers of 2, and upper and lower case options are equivalent. Only integer 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
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System Administration Commands metattach(1M)
Example 1 Concatenating a New Slice to a Metadevice This example concatenates a single new slice to an existing metadevice, Volume.1. Afterwards, you would use the growfs(1M) command to expand the file system.# metattach Volume.1 /dev/dsk/c0t1d0s2
Example 2 Detaching Logging Device from Trans MetadeviceThis example detaches the logging device from a trans meta-
device d9. Notice that you do not have to specify the log-
ging 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 pro-
tected against single-device failure.
Example 4 Expanding a Soft PartitionThe following example expands a soft partition, d42, attach-
ing all space available on the underlying device.# metattach d42 all
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System Administration Commands metattach(1M)
When you add additional space to a soft partition, the addi-
tional space is taken from any available space on the sliceand might not be contiguous with the existing soft parti-
tion.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 -M /export /dev/md/rdsk/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 expandSunOS 5.11 Last change: 20 Jun 2006 6
System Administration Commands metattach(1M)
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 AlignmentThis example shows how to set the alignment of the soft par-
tition 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 attri-
butes:____________________________________________________________
| ATTRIBUTE TYPE | ATTRIBUTE VALUE |
|_____________________________|_____________________________|
| Availability | storage/svm ||_____________________________|_____________________________|
| Interface Stability | Committed ||_____________________________|_____________________________|
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)SunOS 5.11 Last change: 20 Jun 2006 7
System Administration Commands metattach(1M)
WARNINGS This section provides information regarding warnings fordevices 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 theSolaris Operating System with a 32-bit kernel or if you
expect to use a version 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 thatexisted on the mirror prior to running metadetach. In par-
ticular, if the -f option was needed, the metadevice and
mirror probably do not contain the same data. NOTESTrans metadevices have been replaced by UFS logging. Exist-
ing trans devices are not logging. They pass data directlythrough to the underlying device. See mount_ufs(1M) for more
information about UFS logging.SunOS 5.11 Last change: 20 Jun 2006 8