metattach is used to add submirrors to a mirror, add logging devices to trans devices, grow metadevices, or grow 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 one-to-four-way mirrors. Thus, you can only attach a metadevice to a mirror if there are three or fewer submirrors beneath the mirror. Once a new metadevice is attached to a mirror, metattach will automatically start a resync operation to the new submirror.

Attaching a new logging device to a busy trans metadevice is allowed, although a trans metadevice will start using its new logging device only after the trans is idle (after it is unmounted, for example). The busy trans will be in an Attaching state (metastat) until the logging device is actually attached. Attaching a logging device in the Hard Error or Error state (metastat) is not allowed.

metadetach is used to detach submirrors from mirrors and to detach 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 via 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. Once detached, the logging device is no longer part of the trans, thus the trans is no longer logging and all benefits of logging are lost. Any information on the logging device that pertains to the master device is written to the master device before the logging device is detached.

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.

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

-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 will have no effect, because the mirrors must be resynchronized before one of them can be detached.

-h

Displays a usage message.

-i size

Specifies 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 will be carried forward on all stripes that follow.

-s setname

Specifies the name of the diskset on which the metattach command or the metadetach command will work. Using the -s option will cause the command to perform its administrative function within the specified diskset. Without this option, the command will perform its function on local metadevices.

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

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

log

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

metadevice

Specifies the name of the metadevice to be attached to the mirror as a submirror. This metadevice must have been previously created by the metainit command.

mirror

Specifies the mirror.

RAID

Specifies the metadevice name of the RAID5 metadevice.

size

Specifies 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 terabytes, and B or b for blocks (sectors).

softpart

Specifies the metadevice name of the existing soft partition.

submirror

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

trans

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

The following exit values are returned:

0

Successful completion.

>0

An error occurred.

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

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

Solaris Volume Manager Administration Guide

When a submirror is detached from its mirror, the data on the metadevice may 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.