After a reboot, I got greeted with this error :
[email protected]:~# zpool status pool: rpool state: DEGRADED status: One or more devices could not be used because the label is missing or invalid. Sufficient replicas exist for the pool to continue functioning in a degraded state. action: Replace the device using 'zpool replace'. see: http://zfsonlinux.org/msg/ZFS-8000-4J scan: resilvered 10.1G in 0h26m with 0 errors on Mon Mar 27 16:35:05 2017 config: NAME STATE READ WRITE CKSUM rpool DEGRADED 0 0 0 mirror-0 DEGRADED 0 0 0 sda ONLINE 0 0 0 2748060340541772838 UNAVAIL 0 0 0 was /dev/sdb2 sdc2 ONLINE 0 0 0 sdd2 ONLINE 0 0 0
I replaced the disk, and then forced a replace.
zpool replace -f rpool 2748060340541772838 /dev/sdb
zpool replace [-f] $poolname $old_device $new_device
The status is now :
[email protected]:~# zpool list NAME SIZE ALLOC FREE EXPANDSZ FRAG CAP DEDUP HEALTH ALTROOT rpool 928G 10.2G 918G 16.0E 3% 1% 1.00x DEGRADED - [email protected]:~# zpool status pool: rpool 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 Tue Mar 28 11:31:57 2017 14.3M scanned out of 10.2G at 1.02M/s, 2h50m to go 14.2M resilvered, 0.14% done config: NAME STATE READ WRITE CKSUM rpool DEGRADED 0 0 0 mirror-0 DEGRADED 0 0 0 sda ONLINE 0 0 0 replacing-1 UNAVAIL 0 0 0 2748060340541772838 UNAVAIL 0 0 0 was /dev/sdb2 sdb ONLINE 0 0 0 (resilvering) sdc2 ONLINE 0 0 0 sdd2 ONLINE 0 0 0 errors: No known data errors