A few things work in unexpected ways,
or not at all, on distributed NFS filesystems:
File operations not supported
File locking operations on directories are not supported on remote filesystems.
Append mode and atomic writes are not guaranteed to work on
remote files accessed by more than one client simultaneously.
Applications that use mandatory locking are not supported over
NFS.
Cannot access remote devices
With NFS, it is not possible to access a remote-mounted device
or any other character or block-special file.
Cannot access indirect filesystems
Under NFS,
it is not possible to access a filesystem indirectly.
For example, you may not use a server machine to access
a filesystem on a third server machine. All NFS
access must be direct from server to client.
Cannot access server inodes
If an NFS client running SCO® Open Desktop® Release 3.0
or earlier tries to mount filesystems from an SCO OpenServer Release 5
NFS server, some of the exported files may not be available.
This is because SCO OpenServer filesystems such as DTFS and
HTFS support a greater
number of inodes (2^32) than filesystems in earlier releases (2^16).
We recommend that the number of inodes in a server's exported
filesystem should not exceed the maximum number that a client
can address.