[OpenAFS] bogus file dates

[Jeffrey Hutzelman]

On Thursday, May 06, 2004 11:59:02 -0400 Gregg Tracton 
<tracton@med.unc.edu> wrote:

>
> This is a real show stopper: a reason for us to move from AFS to another
> less-featured shared disk solution.
>
> We see files written into our afs space with bogus date timestamps,
> originating from windows, linux, and solaris clients. The timestamps
> display, depending on the client viewing the timestamp, as either
> December 31, 1969 or a day in 2033. It does not matter which of our 2 afs
> file servers contains the volume. The problem is rare (once daily) and
> not reproducible.
>
> --> Can anyone give clues as to where to start looking?
>
> This really messes up incremental backup and other programs that depend
> on dates being correct. I've been doing Level 0 backups but our disk
> usage will shortly exceed our tape capacity so I need to move to
> incremental backups or drop AFS all together.


The timestamps that are visible to you through the filesystem are set by 
the client.  If you have a client whose clock is off, it will set bad 
timestamps on the files it writes.

However, if you actually use 'vos dump' or an AFS-aware backup system, the 
timestamps that are visible to you are not used for incremental backups. 
The fileserver keeps a second set of timestamps, which cannot be affected 
by clients and are not made visible to you by the cache manager.  It is 
these timestamps which are used in constructing incremental volume dumps.

-- Jeffrey T. Hutzelman (N3NHS) <jhutz+@cmu.edu>
   Sr. Research Systems Programmer
   School of Computer Science - Research Computing Facility
   Carnegie Mellon University - Pittsburgh, PA