[OpenAFS] Re: AFS db portability upgrading db server etc

Andrew Deason adeason@sinenomine.net
Tue, 2 Apr 2013 12:03:02 -0500

On Tue, 02 Apr 2013 09:59:44 -0400
John W Sopko Jr <sopko@cs.unc.edu> wrote:

> I would first shutdown the AFS db instances on the old server so one
> of our other db servers would become the sync master. I was then going
> to rsync the db files to the new 64 bit server from the old server and
> turn on the afs db server instances. Or should I just leave the
> /usr/afs/db directory empty and the new machine will sync the
> databases over?

It will sync by itself. It might be faster if you copy it over manually,
but it shouldn't make much of a difference.

> If I do a mdsum checksum on the db's I notice the lowest IP server has
> a different checksum then the other 2 secondary db servers which have
> the same checksum. Are the dbs portable? Thanks for any
> recommendations.

The dbs are portable. If you skip the first 8 bytes or so (or maybe it's
just 4 bytes), they should be identical. The actual db files on disk
contain a header preceding the actual database, and part of the space
for the header is unused and can contain different values.

Of course, that assumes the database isn't changing :) If you suspect
they are problematically different, you can diff a hexdump output of the
database, and see how many bytes differ and what ranges, etc.

Andrew Deason