[OpenAFS] Incremental backups

[Tom Fitzgerald]

> We also ran into
> problems with time between running on the command line vs.
> cron.  Our software compares time stamps in the vos dump
> headers to avoid these types of problems.

I'm not sure what you mean here.  Your software assumed the
current wallclock time was the time cron normally ran it, which
was wrong when it was run from the command line?

The script here creates a timestamp file before running vos backup,
then does incrementals relative to the timestamp file, to avoid
having to pick through the dump file (and deal with potential
future format changes), which should suffice.