After a device is taken offline, it can be brought online again by using the zpool online command. For example:
# 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 with the newly available device. Note that you cannot use bring a device online to replace a disk. If you take a device offline, replace the device, and try to bring it online, it remains in the faulted state.
If you attempt to bring 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 displayed on the console or written to the /var/adm/messages file. For example:
SUNW-MSG-ID: ZFS-8000-D3, TYPE: Fault, VER: 1, SEVERITY: Major EVENT-TIME: Wed Jun 30 14:53:39 MDT 2010 PLATFORM: SUNW,Sun-Fire-880, CSN: -, HOSTNAME: neo SOURCE: zfs-diagnosis, REV: 1.0 EVENT-ID: 504a1188-b270-4ab0-af4e-8a77680576b8 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 about replacing a faulted device, see Resolving a Missing Device.
You can use the zpool online -e command to expand the pool's size when a smaller disk is replaced by a larger disk. By default, pool size is not expanded to its full size unless the autoexpand pool property is enabled. You can expand the pool size automatically when a smaller disk is replaced by a larger disk by using the zpool online -ecommand even if the disk is already online or if the disk is currently offline. For example:
# zpool online -e tank c1t13d0 |