[Linux-cluster] GFS lockups ?

[Marc Grimme]

On Thursday 09 October 2008 01:24:51 Janar Kartau wrote:
> Hi,
> Recently our three-node webserver cluster started randomly crashing. I
> never had time to investigate what the problem was, cause i needed to
> bring them back online again. But it seemed like alla Apache processes
> just hang (couldn't even kill them).. waiting for something. The only
> thing that helped, was a reboot for all or couple of the nodes. Anyway,
> today i encountered this problem at night and i could look into it a
> little more. I noticed that some of the GFS filesystems were
> unaccessable (we have 5 of them, mounted on every nide) and of the nodes
> was completely unaccessable. So i guessed that this half-dead node was
> holding locks on the filesystems or sth. Did a hard reset on this dead
> node and all stabilized.
> Absolutely no cluster/GFS errors in the logs (besides the ones which
> tell that the half-dead node was leaving the cluster when i reset it).
> Nodes have CentOS 4.6 installed (2.6.9-67.0.7.ELsmp, dlm-1.0.7-1,
> GFS-6.1.15-1, cman-1.0.17-0.el4_6.5). We use EMC CX3-10c for GFS storage
> (over iSCSI) and EMC PowerPath for multipathing. Separate VLAN is used
> for CMAN/DLM traffic.
> Please give me ideas how to solve this or atleast some debugging tips as
> it's happening twice a day now and seems i simply can't help it. :(

Could you provide more information like relevant syslogs and console messages?

Are you using php with sessions?

-- 
Gruss / Regards,

Marc Grimme
http://www.atix.de/               http://www.open-sharedroot.org/