To add a new device to an existing virtual device, use the following command:
# zpool attach pool existing-device new-device
You can use the zpool detach command to detach a device provided one of the following conditions applies:
The device belongs to a mirrored pool configuration.
In a RAID-Z configuration, the detached device is replaced by another physical device or by a spare.
Outside of these conditions, detaching a device generates an error similar to the following:
cannot detach c1t2d0: only applicable to mirror and replacing vdevs
The following examples show how to apply zfs attach commands.
Example 9 Converting a Two-Way Mirrored Storage Pool to a Three-Way Mirrored Storage PoolIn this example, mpool is an existing two-way mirror pool. It is converted into a three-way mirror pool by attaching c2t1d0, the new device, to the existing device c1t1d0. The newly attached device is immediately resilvered.
# zpool attach mpool c1t1d0 c2t1d0
# zpool status mpool
pool: mpool
state: ONLINE
scrub: resilver completed after 0h0m with 0 errors on Fri Jan 8 12:59:20 2010
config:
NAME STATE READ WRITE CKSUM
mpool ONLINE 0 0 0
mirror-0 ONLINE 0 0 0
c0t1d0 ONLINE 0 0 0
c1t1d0 ONLINE 0 0 0
c2t1d0 ONLINE 0 0 0 592K resilveredAttached device creates a 3-way mirror pool
errors: No known data errors
Example 10 Converting a Nonredundant Storage Pool to a Mirrored Storage Pool
The zpool attach command also enables you to convert a storage pool or a log device from a nonredundant to a redundant configuration.
The following example shows the status of the nonredundant pool system1 before and after it is converted into a redundant pool.
# zpool status system1
pool: system1
state: ONLINE
scrub: none requested
config:
NAME STATE READ WRITE CKSUM
system1 ONLINE 0 0 0
c0t1d0 ONLINE 0 0 0
errors: No known data errors
# zpool attach system1 c0t1d0 c1t1d0
# zpool status system1
pool: system1
state: ONLINE
scrub: resilver completed after 0h0m with 0 errors on Fri Jan 8 14:28:23 2010
config:
NAME STATE READ WRITE CKSUM
system1 ONLINE 0 0 0Pool becomes mirrored
mirror-0 ONLINE 0 0 0
c0t1d0 ONLINE 0 0 0
c1t1d0 ONLINE 0 0 0 73.5K resilvered
errors: No known data errors