ZFS Hardware Maintenance
To replace a hard drive with another device, run:
# zpool replace <pool-name> <old-disk> <new-disk>
To offline a failing drive, run:
# zpool offline <pool-name> <disk-name>
(A -t flag allows the disk to come back online after a reboot.)
Once the drive has been physically replaced, run the replace command against the device:
# zpool replace <pool-name> <device-name>
After an offlined drive has been replaced, it can be brought back online:
# zpool online <pool-name> <disk-name>
Firmware upgrades may cause the disk device ID to change. ZFS should be able to update the device ID automatically, assuming that the disk was not physically moved during the update. If necessary, the pool can be exported and re-imported to update the device IDs.