I have two 4 TB USB drives in a mirrored zpool running on Debian 7.2. About once a week, the zpool will go into a degraded state with the following error:
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 XXXK in 0h0m with 0 errors on [date] config: NAME STATE READ WRITE CKSUM my-zpool-name DEGRADED 0 0 0 mirror-0 DEGRADED 0 0 0 scsi-SSeagate_Backup+_Desk_MaNA5R1GNK UNAVAIL 4 1 0 corrupted data scsi-SSeagate_Backup+_Desk_MaNA5R1GNP ONLINE 0 0 0
In once instance, there was no corrupted data.
In all instances, the device was never unplugged from my system. The zpool will stay in the degraded state until I do a "zpool clear my-zpool-name", at which point it will resilver and its state will be "ONLINE" again. It always happens to the same device.
Any idea what could be causing this? Could it be that one of my USB drives is defective and needs to be replaced? I'm still quite new to ZFS so any help will be much appreciated!