[Linux-cluster] optimising DLM speed?

[Alan Brown]

The setup described is all on RHEL5.6.

Fileserver filesystems are each mounted on one cluster node only 
(scattered  across nodes) and then NFS exported as individual services 
for portability. (That exposed a major race condition with exportfs as 
it's not parallel aware in any way, shape or form)

Imapserver filesystems are mounted on one node and ALL imap activity 
happens on that node (hot standby)

Up to EL5.6 this has been pretty unstable, panicing regularly under load 
and losing filesystem to a FC driver bug I'll describe separately.