Fun with NFS

I once read a story of a man who constantly challenged the remaining milage indicator on his car's instrument cluster. As a result, he constantly ran out of fuel, proving that the car's computer did it's job. When I read this story, I thought experience must win his trust at some point, and that the whole thing is just silly.

However, I think I have been doing pretty much the same thing with NFS. I constantly challenge the proven knowledge that you should not run mail on NFS.

We currently host quite a few Virtual Servers, based on the Linux VServer project. At some point we ran out of local diskspace, plopped in a big ol' chunk of diskspace in another dedicated machine and started running virtual hosts from NFS. These mostly work fine, except in the case of postfix. Postfix has come a long way in allowing mailboxes on NFS, but it definitly does not like it when you put it's queues on NFS.

Such were my experiences today: Postfix drops my test emails straight into the corrupt queue. It looks like it gets worse if you add amavis into the mix. I eventually mounted a local filesystem onto /var/spool/postfix and tried it again, and this time it worked perfectly.

Moral of the story? Don't challenge NFS. It has been proven to suck at doing mail.