[Linux-cluster] GFS2 and D state HTTPD processes

[Steven Whitehouse]

Hi,

On Fri, 2010-02-26 at 16:52 +0100, Emilio Arjona wrote:
> Hi,
> 
> we are experiencing some problems commented in an old thread:
> 
> http://www.mail-archive.com/linux-cluster@redhat.com/msg07091.html
> 
> We have 3 clustered servers under Red Hat 5.4 accessing a GFS2 resource.
> 
> fstab options:
> /dev/vg_cluster/lv_cluster /opt/datacluster gfs2
> defaults,noatime,nodiratime,noquota 0 0
> 
> GFS options:
> plock_rate_limit="0"
> plock_ownership=1
> 
> httpd processes run into D status sometimes and the only solution is
> hard reset the affected server.
> 
> Can anyone give me some hints to diagnose the problem?
> 
> Thanks :)
> 
Can you give me a rough idea of what the actual workload is and how it
is distributed amoung the director(y/ies) ?

This is often down to contention on glocks (one per inode) and maybe
because there is a process of processes writing a file or directory
which is in use (either read-only or writable) by other processes.

If you are using php, then you might have to strace it to find out what
it is really doing,

Steve.

> --
> 
> Emilio Arjona.
> 
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