On Thu, 1 Jul 2004 at 8:09am, donald.ritchey AT exeloncorp DOT com wrote

> Hopefully this won't be too hard to resolve, but we are having some problems
> with resource conflicts between Amanda and the software package that is the
> reason we are running the server.  (Guess who looses in the management
> tug-of-war on this one.)
> 
> Several times during the Amanda backup of one of our servers, the CPU
> utilization goes up to 100 percent and the system becomes very unresponsive.
> The finger has been pointed at Amanda since the high runner processes at
> this point are vdump and gzip (the systems are Tru64 UNIX clusters, thus
> vdump).  I have changed the backup type from client-compress to
> server-compress, but that does not completely resolve the problem, we still
> see the slowdowns.

So I take it that this box isn't the amanda server?  And, after moving to 
server-compress, you're still seeing high usage from vdump *and* gzip?

> How do I throttle back the Amanda processes without killing my backups
> entirely?  

Well, I have no experience with Tru64, but I don't think that simply 
reading data off disk (and compressing a string of text, which is 
what that gzip is doing -- compressing the index) should peg the CPU.  
Can you replicate that problem without amanda (running vdump by hand, 
e.g.).  Are there parameters you can tweak to make the disks more 
efficient?

> Do I have to go into the source and start hacking on Amanda to add a new
> "feature"?

One thing you could try would be to make the vdump amanda calls a script 
that "nice"s the actual vdump process.  Is tar an option?  That may be 
more efficient perhaps?

-- 
Joshua Baker-LePain
Department of Biomedical Engineering
Duke University