NFS can frequently cause hanging guests if the server goes away, leaving the filesystem mounted. Locking is often a problem, for example if you've got ~ mounte

NFS can frequently cause hanging guests if the server goes away, leaving the filesystem mounted. Locking is often a problem, for example if you've got ~ mounted on NFS and you're delivering mail to mboxes - obviously maildirs sidestep that particular problem. Firewalling is a real pain, as is access-control and UID remapping. (These are more concerns when you have a single server sharing a tree to multiple clients.) Finally failover & high-availablity are hard because you can't do transitions terribly easily, although hacks exist using automounter, etc.