[Ocfs2-users] OCFS2 performance and debug help

[Joel Becker]

On Sun, Apr 08, 2012 at 10:54:52AM -0700, Jay V wrote:
> I have a similar blocking/hanging/stall issue. On Oracle 6.2/x64. We
> are running OCFS2 on 3 partitions about 14-15TB each. One of the
> partitions has been running extremely slowly too. They are running on
> the same hardware-- LSI HW Raid Cards and Enterprise Drives. I am
> running over drbd and nfsd.

	How do drbd and nfsd fit in your scheme?  nfsd is on top of
ocfs2, right?  You're exporting ocfs2 volumes via NFS?  Can you think of
any differences between the slow partition and the fast ones?
 
> I am getting really slow performance in writes. The process
> [jbd2-drbd-18] seems to be stuck for a long length of time (about 2
> minutes) before it finally commits. This jbd2-drbd2 prevents any other
> writes from happening which stalls the system.

	I'm worried that drbd is doing things slowly and getting in your
way.  But given the slowdown you are replying to, that might not be the
only issue.

> This would be from "ps auxr"
> USER       PID %CPU %MEM    VSZ   RSS TTY      STAT START   TIME COMMAND
> root      6374  0.0  0.0      0     0 ?        D    Apr03   0:28 [jbd2/drbd2-18]
> root      6876  0.0  0.0      0     0 ?        D    Apr06   0:11 [nfsd]
> root      6884  0.0  0.0      0     0 ?        D    Apr06   0:09 [nfsd]
> root      6999  0.0  0.0      0     0 ?        D    Apr06   0:45 [nfsd]
> root      7046  0.0  0.0      0     0 ?        D    Apr06   0:09 [nfsd]
> root      7053  0.0  0.0      0     0 ?        D    Apr06   0:09 [nfsd]
> root      7054  0.0  0.0      0     0 ?        D    Apr06   0:08 [nfsd]
> 
> Running "scan_locks2" shows nothing. Nothing is held up locking wise.
> It seems to happen more with files copying about 1MB or larger. It
> only happens for me on my second partition, but not the other 2. It
> seems to super slow in writes. Reads are fast.
> 
> I hope to find a solution quickly too. I wonder it is because we have
> very large partitions.

	It shouldn't be because of large partitions.  How long have your
partitions been around?  How full are they?

Joel

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