[Ocfs2-users] frozen ocfs2 filesystem under heavy webserver load

[Sunil Mushran]

None of these locks are busy. So they should not be the cause of the 
problem.

Start with the version of ocfs2. Also, which kernel?
What does top say? Is some process spinning?

Also, what does this stresstest entail?

Stephan Hendl wrote:
> Hi,
>
> I use a cluster of 4 nodes with ocfs2 as a webserver cluster. During a stresstest it occurs after a couple of minutes that the webserverprocesses are ideling but the system load is extremely high (abou 150...200) where the waits are very low. After that I cannot interrupt the webserver processes anymore and in some directories a "ls -ls" comes not back - so it seems that the file system has a problem. Only a reset of the server solves the problem ;-((
>
> In the debug mode I can find the following lines as an example:
>
> Lockres: D00000000000000000ccda0fcc1c07e  Mode: Exclusive
> Flags: Initialized Attached
> RO Holders: 0  EX Holders: 0
> Pending Action: None  Pending Unlock Action: None
> Requested Mode: Exclusive  Blocking Mode: Invalid
>
> Lockres: M00000000000000000ccda0fcc1c07e  Mode: Exclusive
> Flags: Initialized Attached
> RO Holders: 0  EX Holders: 0
> Pending Action: None  Pending Unlock Action: None
> Requested Mode: Exclusive  Blocking Mode: Invalid
>
> Lockres: D00000000000000000ccd9ffcc1c07d  Mode: Exclusive
> Flags: Initialized Attached
> RO Holders: 0  EX Holders: 0
> Pending Action: None  Pending Unlock Action: None
> Requested Mode: Exclusive  Blocking Mode: Invalid
>
> Lockres: M00000000000000000ccd9ffcc1c07d  Mode: Exclusive
> Flags: Initialized Attached
> RO Holders: 0  EX Holders: 0
> Pending Action: None  Pending Unlock Action: None
> Requested Mode: Exclusive  Blocking Mode: Invalid
>
> Could it be that two servers like to write to the same file and under heavy load the clusterd processes cannot handle this?
>
> Regards und thanks,
> Stephan
>