kern/164252: Journal Overflow

[Oliver]

>Number:         164252
>Category:       kern
>Synopsis:       Journal Overflow
>Confidential:   no
>Severity:       critical
>Priority:       medium
>Responsible:    freebsd-bugs
>State:          open
>Quarter:        
>Keywords:       
>Date-Required:
>Class:          sw-bug
>Submitter-Id:   current-users
>Arrival-Date:   Tue Jan 17 18:20:07 UTC 2012
>Closed-Date:
>Last-Modified:
>Originator:     Oliver
>Release:        9.0-RELEASE
>Organization:
n/a
>Environment:
FreeBSD test 9.0-RELEASE FreeBSD 9.0-RELEASE #0: Tue Jan  3 07:46:30 UTC 2012     root at farrell.cse.buffalo.edu:/usr/obj/usr/src/sys/GENERIC  amd64
>Description:
I'm running some performance tests with iozone to see which filesystem/volume manager/raid version/... fits my needs best.

After running the test on top of ZFS I destroyed the pool and created a freebsd-ufs partition on the "empty" drive. Here the output of "gpart show"

=>       34  976773101  ada0  GPT  (465G)
         34  976773101     1  freebsd-ufs  (465G)

I then labeled the partition ada0p1 with gjournal and created a new UFS2 on top of ada0p1.journal with journaling enabled (-J).

Then the partiton was mounted and the iozone test was started inside. The command was "iozone -RA -g 16G". When starting to write 1GB of data in 64k chunks, the system crashed (check the - literally - screenshot attached).

The system wasn't even able to write more than 2GB of the 8GB memory back to disk before it completly froze.

I did the exact same test with this system and ZFS on the empty disk and everything worked as expected.

I wasn't able to attach the screenshot, so I uploaded it here: http://img515.imageshack.us/img515/9622/gjournal.jpg

If you have any questions just contact me.

KR, Grimeton

>How-To-Repeat:
- Setup 9.0-RELEASE on one harddrive
- Fetch ports, compile benchmarks/iozone
- create a GPT scheme on another, empty, disk
- setup a freebsd-ufs partition
- label the partition with gjournal
- create UFS2 on top of the journaled partiton with journaling enabled (-J)
- mount the new fs to /test
- cd to /test
- start iozone like "iozone -Ra -g 16G"
- wait and watch it crash
>Fix:
No clue.

>Release-Note:
>Audit-Trail:
>Unformatted: