[Linux-cluster] Filesystem Freeze

[Robert Peterson]

Röthlein Michael (RI-Solution) wrote:
> Hello,
>  
> We use GFS for about 1 year now on a 4 node cluster connected to a SAN. In the past weeks nearly every day we had troubles desribed here: http://www.open-sharedroot.org/faq/troubleshooting-guide/system-failures/the-whole-cluster-freezes/ as "Freeze of filesystem"
>> There you will not see anything in the syslogs. The only thing you will see is rapidly increasing load on the system an 
>> rapidly increasing amounts of processes in the D State (means waiting for I/O). Here a lock is hung and any process 
>> accessing the resource (normally directory) locked by this lock will end up in the processstate D. 
>  
> Is there any sure way to determine which node causes the lock or any fix for this issue? 
> We use this cluster as web server running apache 2.
> 
> Thanks in advance
> 
> Yours
> 
> Michael
Hi Michael,

Maybe your best bet is to save off a sysrq-t ("Magic Sysrq") output from all nodes 
in the cluster as soon as you notice the hang.  Then open a bugzilla and attach 
all of these outputs to the bz, along with version information, etc.

Regards,

Bob Peterson
Red Hat Cluster Suite