New ZFSv28 patchset for 8-STABLE: Kernel Panic

[Jean-Yves Avenard]

Hi

On 27 December 2010 16:04, jhell <jhell at dataix.net> wrote:

> 1) Set vfs.zfs.recover=1 at the loader prompt (OK set vfs.zfs.recover=1)
> 2) Boot into single user mode without opensolaris.ko and zfs.ko loaded
> 3) ( mount -w / ) to make sure you can remove and also write new
> zpool.cache as needed.
> 3) Remove /boot/zfs/zpool.cache
> 4) kldload both zfs and opensolaris i.e. ( kldload zfs ) should do the trick
> 5) verify that vfs.zfs.recover=1 is set then ( zpool import pool )
> 6) Give it a little bit monitor activity using Ctrl+T to see activity.

Ok..

I've got into the same situation again, no idea why this time.

I've followed your instructions, and sure enough I could do an import
of my pool again.

However, wanted to find out what was going on..
So I did:
zpool export pool

followed by zpool import

And guess what ... hanged zpool again.. can't Ctrl-C it, have to reboot..

So here we go again.
Rebooted as above.
zpool import pool -> ok

this time, I decided that maybe that what was screwing things up was the cache.
zpool remove pool ada1s2 -> ok
zpool status:
# zpool status
  pool: pool
 state: ONLINE
 scan: scrub repaired 0 in 18h20m with 0 errors on Tue Dec 28 10:28:05 2010
config:

	NAME        STATE     READ WRITE CKSUM
	pool        ONLINE       0     0     0
	  raidz1-0  ONLINE       0     0     0
	    ada2    ONLINE       0     0     0
	    ada3    ONLINE       0     0     0
	    ada4    ONLINE       0     0     0
	    ada5    ONLINE       0     0     0
	    ada6    ONLINE       0     0     0
	    ada7    ONLINE       0     0     0
	logs
	  ada1s1    ONLINE       0     0     0

errors: No known data errors

# zpool export pool -> ok
# zpool import pool -> ok
# zpool add pool cache /dev/ada1s2 -> ok
# zpool status
  pool: pool
 state: ONLINE
 scan: scrub repaired 0 in 18h20m with 0 errors on Tue Dec 28 10:28:05 2010
config:

	NAME        STATE     READ WRITE CKSUM
	pool        ONLINE       0     0     0
	  raidz1-0  ONLINE       0     0     0
	    ada2    ONLINE       0     0     0
	    ada3    ONLINE       0     0     0
	    ada4    ONLINE       0     0     0
	    ada5    ONLINE       0     0     0
	    ada6    ONLINE       0     0     0
	    ada7    ONLINE       0     0     0
	logs
	  ada1s1    ONLINE       0     0     0
	cache
	  ada1s2    ONLINE       0     0     0

errors: No known data errors

# zpool export pool -> ok

# zpool import
load: 0.00  cmd: zpool 405 [spa_namespace_lock] 15.11r 0.00u 0.03s 0% 2556k
load: 0.00  cmd: zpool 405 [spa_namespace_lock] 15.94r 0.00u 0.03s 0% 2556k
load: 0.00  cmd: zpool 405 [spa_namespace_lock] 16.57r 0.00u 0.03s 0% 2556k
load: 0.00  cmd: zpool 405 [spa_namespace_lock] 16.95r 0.00u 0.03s 0% 2556k
load: 0.00  cmd: zpool 405 [spa_namespace_lock] 32.19r 0.00u 0.03s 0% 2556k
load: 0.00  cmd: zpool 405 [spa_namespace_lock] 32.72r 0.00u 0.03s 0% 2556k
load: 0.00  cmd: zpool 405 [spa_namespace_lock] 40.13r 0.00u 0.03s 0% 2556k

ah ah !
it's not the separate log that make zpool crash, it's the cache !

Having the cache in prevent from importing the pool again....

rebooting: same deal... can't access the pool any longer !

Hopefully this is enough hint for someone to track done the bug ...