RE: tmpfs, NFS, file handles

[Lever, Charles]

> That means you are only hashing inodes exported by NFS, and you have
> a pretty good guarantee of uniqueness (providing time doesn't go
> backwards).

this may be obvious... apologies.

don't use the TOD directly -- it can go backwards if ntpd or an admin
sets it back.  better to use a monotonically increasing number that
you completely control yourself.

also, if your timer resolution isn't good enough, a window opens 
where two generated "uniquifiers" can be the same for all intents
and purposes.

if there's nothing else we've learned from NFS, it's that using
timestamps is a lousy way of managing cache coherency and file
identity.  ;-)