raidz2 should support two disks being offline. The kernel implementation does not support this. Noted but not problem reported here: http://lists.freebsd.org/pipermail/freebsd-stable/2010-February/054862.html How-To-Repeat: I have two raidz2 virtual devices in the tank pool. # zpool status -v pool: tank state: ONLINE status: The pool is formatted using an older on-disk format. The pool can still be used, but some features are unavailable. action: Upgrade the pool using 'zpool upgrade'. Once this is done, the pool will no longer be accessible on older software versions. scrub: scrub in progress for 0h11m, 3.30% done, 5h40m to go config: NAME STATE READ WRITE CKSUM tank ONLINE 0 0 0 raidz2 ONLINE 0 0 0 ada10 ONLINE 0 0 0 ada11 ONLINE 0 0 0 ada12 ONLINE 0 0 0 ada13 ONLINE 0 0 0 ada14 ONLINE 0 0 0 raidz2 ONLINE 0 0 0 ada5 ONLINE 0 0 0 ada6 ONLINE 0 0 0 ada7 ONLINE 0 0 0 ada8 ONLINE 0 0 0 ada9 ONLINE 0 0 0 spares ada0 AVAIL ada1 AVAIL ada2 AVAIL ada3 AVAIL ada4 AVAIL # zpool offline tank ada10 (works) # zpool offline tank ada11 cannot offline ada11: no valid replicas # zpool status -v pool: tank state: DEGRADED status: One or more devices has experienced an unrecoverable error. An attempt was made to correct the error. Applications are unaffected. action: Determine if the device needs to be replaced, and clear the errors using 'zpool clear' or replace the device with 'zpool replace'. see: http://www.sun.com/msg/ZFS-8000-9P scrub: scrub in progress for 0h21m, 5.78% done, 5h51m to go config: NAME STATE READ WRITE CKSUM tank DEGRADED 0 0 0 raidz2 DEGRADED 0 0 0 ada10 OFFLINE 0 10.6K 0 ada11 ONLINE 0 0 0 ada12 ONLINE 0 0 0 ada13 ONLINE 0 0 0 ada14 ONLINE 0 0 0 raidz2 ONLINE 0 0 0 ada5 ONLINE 0 0 0 ada6 ONLINE 0 0 0 ada7 ONLINE 0 0 0 ada8 ONLINE 0 0 0 ada9 ONLINE 0 0 0 spares ada0 AVAIL ada1 AVAIL ada2 AVAIL ada3 AVAIL ada4 AVAIL # truss zpool offline tank ada11 .. ioctl(2,0xcc285a05 { IORW 0x5a('Z'), 5, 3112 },0xffff9ec0) = 0 (0x0) ioctl(2,0xcc285a0d { IORW 0x5a('Z'), 13, 3112 },0xffff9b00) ERR#16 'Device busy' write(2,"cannot offline ada11: no valid r"...,40) ERR#19 'Operation not supported by device' I don't believe this is affected by the current scrub status.
Responsible Changed From-To: freebsd-bugs->freebsd-fs Over to maintainer(s).
State Changed From-To: open->suspended This problem is fixed in recent ZFS, but the fix is too intrusive to back-port it. It has to wait for new ZFS import. BTW. This issue also exists for N-way mirrors where N > 2.
batch change: For bugs that match the following - Status Is In progress AND - Untouched since 2018-01-01. AND - Affects Base System OR Documentation DO: Reset to open status. Note: I did a quick pass but if you are getting this email it might be worthwhile to double check to see if this bug ought to be closed.
Per comment #2.