zfs replace faulty disk

The disk already crashed. We have already pull it out and replace it with a good one. Now, we just need to fix zpool setup.

First we put the disk offline.

# zpool offline opt2 14610995796361758680
# zpool status -v opt2
  pool: opt2
 state: DEGRADED
status: One or more devices has been taken offline by the administrator.
        Sufficient replicas exist for the pool to continue functioning in a
        degraded state.
action: Online the device using 'zpool online' or replace the device with
        'zpool replace'.
  scan: scrub repaired 0 in 21h9m with 0 errors on Tue Jul 25 00:42:02 2017
config:

        NAME                      STATE     READ WRITE CKSUM
        opt2                      DEGRADED     0     0     0
          raidz1-0                DEGRADED     0     0     0
            da3                   ONLINE       0     0     0
            da4                   ONLINE       0     0     0
            14610995796361758680  OFFLINE      0     0     0  was /dev/da5

And then we replace it with the new device

# zpool replace opt2 da5 /dev/da5
# zpool status -v opt2
  pool: opt2
 state: DEGRADED
status: One or more devices is currently being resilvered.  The pool will
        continue to function, possibly in a degraded state.
action: Wait for the resilver to complete.
  scan: resilver in progress since Sun Aug 27 11:21:53 2017
        28.5G scanned out of 4.77T at 96.7M/s, 14h18m to go
        9.50G resilvered, 0.58% done
config:

        NAME                        STATE     READ WRITE CKSUM
        opt2                        DEGRADED     0     0     0
          raidz1-0                  DEGRADED     0     0     0
            da3                     ONLINE       0     0     0
            da4                     ONLINE       0     0     0
            replacing-2             OFFLINE      0     0     0
              14610995796361758680  OFFLINE      0     0     0  was /dev/da5/old
              da5                   ONLINE       0     0     0  (resilvering)

errors: No known data errors