RE: tmpfs, NFS, file handles

From: Lever, Charles (Charles.Lever@netapp.com)
Date: Thu Feb 21 2002 - 11:16:04 EST


> 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. ;-)
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