Once a device is taken offline, it can be restored by using the zpool online command:
# zpool online tank c1t0d0 bringing device c1t0d0 online |
When a device is brought online, any data that has been written to the pool is resynchronized to the newly available device. Note that you cannot use device onlining to replace a disk. If you offline a device, replace the drive, and try to bring it online, it remains in the faulted state.
If you attempt to online a faulted device, a message similar to the following is displayed:
# zpool online tank c1t0d0 warning: device 'c1t0d0' onlined, but remains in faulted state use 'zpool replace' to replace devices that are no longer present |
You might also see the faulted disk message from fmd.
SUNW-MSG-ID: ZFS-8000-D3, TYPE: Fault, VER: 1, SEVERITY: Major EVENT-TIME: Fri Aug 28 14:08:39 MDT 2009 PLATFORM: SUNW,Sun-Fire-T200, CSN: -, HOSTNAME: neo2 SOURCE: zfs-diagnosis, REV: 1.0 EVENT-ID: 9da778a7-a828-c88a-d679-c9a7873f4808 DESC: A ZFS device failed. Refer to http://sun.com/msg/ZFS-8000-D3 for more information. AUTO-RESPONSE: No automated response will occur. IMPACT: Fault tolerance of the pool may be compromised. REC-ACTION: Run 'zpool status -x' and replace the bad device. |
For more information on replacing a faulted device, see Resolving a Missing Device.
You can use the zpool online -e command to expand a LUN. By default, a LUN that is added to a pool is not expanded to its full size unless the autoexpand pool property is enabled. You can expand the LUN automatically by using the zpool online -ecommand even if the LUN is already online or if the LUN is currently offline. For example:
# zpool online -e tank c1t13d0 |