# kernel panic on ZFS root when writing to RAIDZ



## saoirse87 (Feb 27, 2011)

http://dl.dropbox.com/u/3191453/freebsdZFScrash.jpg

How do I prevent this from happening again?


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## da1 (Feb 27, 2011)

One way would be to tell us what you were doing at the time of the crash, what OS version and platform you have and if you have any special settings.

You know, we aren't magicians; we cannot guess your hardware and software setup.


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## saoirse87 (Feb 27, 2011)

Fair enough da1.

I was running `chown -R $user /nas/backup` my RAIDZ share (on a supermicro aoc-sat2-mv8 SATA controller) when it went down. On 8.1, it's crashed like this for as much as bash-tabbing files on the RAIDZ.


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## Terry_Kennedy (Feb 28, 2011)

saoirse87 said:
			
		

> On 8.1, it's crashed like this for as much as bash-tabbing files on the RAIDZ.


Do all of these crashes happen on the same ZFS pool? I've got 60+TB of files on 3 ZFS pools here and haven't seen anything like that, so I'd suspect something unusual in your pool.

You might try downloading the mfsBSD ISO image w/ ZFS v28 from here and try executing the failing `# chown` in that environment. If it works or you get an error message instead of a panic, that would be informative.

IMPORTANT: You should *not* upgrade your pool(s) to v28 with that image or they won't mount on current 8.x releases. But the v28 code can work with older on-disk versions.


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## da1 (Feb 28, 2011)

saoirse87 said:
			
		

> Fair enough da1.
> 
> I was running `chown -R $user /nas/backup` my RAIDZ share (on a supermicro aoc-sat2-mv8 SATA controller) when it went down. On 8.1, it's crashed like this for as much as bash-tabbing files on the RAIDZ.



Hmm ... interesting; did you try a scrub ? 

One more thing ... try configuring a dump device, maybe you will get more info from the dump if it crashes again.


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## saoirse87 (Feb 28, 2011)

Terry_Kennedy said:
			
		

> Do all of these crashes happen on the same ZFS pool? I've got 60+TB of files on 3 ZFS pools here and haven't seen anything like that, so I'd suspect something unusual in your pool.



[Same ZFS pool and OpenSolaris started complaining about a disk going bad. I'm ordering a 640gb tonight to zpool replace.



			
				Terry_Kennedy said:
			
		

> You might try downloading the mfsBSD ISO image w/ ZFS v28 from here and try executing the failing `# chown` in that environment. If it works or you get an error message instead of a panic, that would be informative.



Will do. Will update.



			
				da1 said:
			
		

> One more thing ... try configuring a dump device, maybe you will get more info from the dump if it crashes again.



[cmd=]ls -la /dev/dumpdev -> /dev/gpt/swap0[/cmd]

What kind of a dump diagnostic is this? I need to read more about it, admittedly.


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## saoirse87 (Mar 5, 2011)

bump. how do I debug the crash guys?

```
lrwxr-xr-x  1 root  wheel  14 Mar  5 12:04 /dev/dumpdev -> /dev/gpt/swap0
```
what next ?!?!


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## Cryptic1911 (Mar 12, 2011)

Did you change anything with memory recently? I have an old mobo that is very picky about having 4 sticks of ram, and last night after I swapped to 8gb (4x2gb) of ram, it wasn't stable with all 4 sticks. I bumped the voltage and it booted just fine, but once I tried to do anything on my zfs pool, it had a kernel panic just like that.


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## User23 (Mar 14, 2011)

Update your system.

This bug was serious for us, maybe you hit the same bug.

http://svn.freebsd.org/viewvc/base?view=revision&revision=219526


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