I''ve been fighting with this raid-z on pool for almost a year now on FreeBSD. Earlier this week I managed to mount it with one corrupted/offline disk. I tried to wipe the disk, and ended up settling with using gpart to make a new partition on it. It resilvered partially, but when I attempted to clear errors (that had been present since I last tried getting the pool to work) it restarted the resilver. After it finished the resilver I tried clearing the errors again, and it again resilvered the pool. A scrub after that finished without any errors. I switched disks around to attach another pool, hoping to migrate data and swap drives out to alleviate this issue. This pool refused to mount after a reboot, reporting I/O errors. I exported the pool, hoping that an import might fix any issues with zpool.cache. It currently won''t import. root at snorri:/dev # zpool import pool: njal id: 7502878427997551002 state: ONLINE status: One or more devices contains corrupted data. action: The pool can be imported using its name or numeric identifier. see: http://illumos.org/msg/ZFS-8000-4J config: njal ONLINE raidz1-0 ONLINE ada4 ONLINE replacing-1 ONLINE 3537756537319650203 UNAVAIL corrupted data ada1p1 ONLINE 1543306220834098718 UNAVAIL corrupted data root at snorri:/dev # zpool import njal cannot import ''njal'': I/O error Destroy and re-create the pool from a backup source. 3537756537319650203 and ada1p1 are the same disk - the former was ada1p2, but no longer has a listing under /dev Thanks, Dan Davis -- http://alpha2delta.blogspot.com/