metattach(1M)
NAME
metattach, metadetach - attach or detach metadevice to or
from a mirror or trans device, or attach space (blocks) to a
soft partition to grow the soft partition
SYNOPSIS
/usr/sbin/metattach [-h]
/usr/sbin/metattach [-s setname] mirror [metadevice]
/usr/sbin/metattach [-s setname] [-i size] concat/stripe
component...
/usr/sbin/metattach [-s setname] RAID component...
/usr/sbin/metattach [-s setname] softpart size
/usr/sbin/metattach [-s setname] trans log
/usr/sbin/metadetach [-s setname] [-f] mirror submirror
/usr/sbin/metadetach [-s setname] [-f] trans
DESCRIPTION
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 inter-
rupting service. To grow the size of a mirror or trans, the
slices must be added to the submirrors or to the master dev-
ices.
Solaris Volume Manager supports storage devices and logical
volumes greater than 1 terabyte (TB) when Solaris is running
a 64-bit 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 inter-
vention.
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 be unavailable. If a system with large volumes is
rebooted under a version of Solaris that lacks large volume
support, Solaris Volume Manager will not start. You must
remove all large volumes before Solaris Volume Manager runs
under another version of the Solaris Operating Environment.
Solaris Volume Manager supports one-to-four-way mirrors. 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 automatically
starts a resync operation to the new submirror.
Attaching a new logging device to a busy trans metadevice is
allowed, although a trans metadevice starts using its new
logging device only after the trans is idle (after it is
unmounted, for example). The busy trans is 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 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.
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.
OPTIONS
Root privileges are required for all of the following
options except -h.
The following options are supported:
-f Force the detaching of metadevices that have com-
ponents 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 size
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 speci-
fied, 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 administra-
tive 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 command.
mirror
The name of the mirror.
RAID The metadevice name of the RAID5 metadevice.
size 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
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 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 Partition
The following example expands a soft partition, d42, by
attaching 150 Mbytes.
# metattach d42 150M
When you add additional space to a soft partition, the addi-
tional space is taken from any available space on the slice
and 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
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
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 | SUNWmdu |
|_____________________________|_____________________________|
SEE ALSO
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
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 Environment with a 32-bit kernel or if you
expect to use a version of the Solaris Operating Environment
that lacks large volume support.
Multi-Way Mirrors
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.
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