We have a few linux file servers, our sysadmin refuses to do any NFS cross mounting, by cross mounting I mean mounting an nfs share from server A on server B and a share from server B on A .Anybody knows if there are any problems with this cross mounting? 
Cross mounting nfs shares on linux servers
mount;nfs
Ordering the bootup of the two servers can be challenging.Ideally, you'd like your servers to recover from a power failure without operator intervention. But, of course, some servers need to come up before otherse.g., maybe you need your firewall up before trying to bring up servers that connect externally. Or, you need your NFS servers up before their clients.One way to do this is to get a smart power strip (e.g., APC managed PDU), and then you can configure power-on delay for each outlet. So you can make sure your firewall and switches turn on first, then your DNS servers, then your NFS servers, etc. Even if you do this manually off a checklist (turn on A, wait for it to boot, turn on B and C, wait for them to boot, ...) you still want simplicity.But you can't do that if A depends on B, but B depends on A. In simple cases, its easy enough to work aroundA and B just need to start up their own NFS server (and export their local filesystems) before attempting to mount any NFS shares (though this is the opposite of the default ordering). Unless of course you wind up with nested paths, where e.g., a local filesystem is mounted underneath an NFS mount. Or where you add a third server, and then maybe shares from A are mounted under ones from B on C.Working around that kind of stuff manually isn't too hard, of course, but you don't want to be doing that after a power failure. You've probably got unplanned problems to solve (e.g., stuff that broke from unexpected power loss, or dependencies you didn't know about), while everyone is complaining about it being down, so its best not to set up known, avoidable problems that'll eat your time.Also, mounting and then re-exporting an NFS share is probably ill-advised, if for no other reason than the network overhead of sending all the data twice. Not like the client can't just mount both servers.edit: One more reasonwhen an NFS server goes down, any processes on a client trying to access that server go into disk (uninterruptible) sleep. That may lead to contagion from one NFS server failing to the other failing (from essential processes going into disk sleep, or running out of resources from cron jobs spawning and not finishing, etc.). (This shows a D in ps, if you're wondering)