[DRBD-user] Mount filesystem on both servers?

[Peter Funk]

Hello,

Stefan Seifert:
...
> But be advised, that running primary/primary with a cluster file system adds 
> much complexity to an already complex system. Most probably, you just want to 
> use NFS to access the files on the primary node from the secondary. Should be 
> enough for most cases and is easier to handle and thus less error prone.

Hmmm... What about file-locking?  

Normally a rpc.statd is required for this to work, which for example on
Ubuntu Linux is started as part of the package/service nfs-common.  
Since rpc.statd will be started by /etc/init.d/nfs-common it is needed 
---as the name `common` already suggests--- on both the NFS server and 
NFS client sides.

Unfortunately /var/lib/nfs which is in turn needed by rpc.statd to start 
up has to be kept on the shared DRBD to avoid stale nfs file locks
on any clients after a failover switch.

Conclusion:
Together with heartbeat it is not that simple to exchange the roles
of the NFS server and the NFS client between two nodes back and fourth.

At least as I insisted on using heartbeat r1 style config files because
I wanted to avoid the fancy and IMHO rather complex XML cluster resource 
manager files introduced with heartbeat 2.x I ran into severe problems
and had to give up for the time being.

I would love to read any clever suggestions to overcome the conflict
outlined above.

Regards, Peter
-- 
Peter Funk, ✉Oldenburger Str.86, D-27777 Ganderkesee
office: ArtCom GmbH, ✉Haferwende 2, D-28357 Bremen, Germany 
tel:+49-421-20419-0 cell:+49-179-640-8878 <http://www.artcom-gmbh.de/>