Backup Central

I use Amanda to backup an iMac running Mac OS X (10.2). The backup runs
perfectly, but the machine is horribly unresponsive while tar is running,
both during the estimate and dump stages. Renice'ing the tar processes
doesn't seem to help, so I'm guessing that it might be an IDE DMA thing,
although I don't know my way around Mac hardware well enough to know.

Has anyone else seen this, and hopefully found a way to lessen the impact?
=2D-=20
Kirk Strauser
In Googlis non est, ergo non est.

On Sun, Feb 15, 2004 at 09:56:40PM -0600, Kirk Strauser wrote:
I use Amanda to backup an iMac running Mac OS X (10.2). The backup runs
perfectly, but the machine is horribly unresponsive while tar is running,
both during the estimate and dump stages. Renice'ing the tar processes
doesn't seem to help, so I'm guessing that it might be an IDE DMA thing,
although I don't know my way around Mac hardware well enough to know.

Has anyone else seen this, and hopefully found a way to lessen the impact?

Can you tell if it is cpu or i/o bound?
For example, do you have "top" or some other utility to say
if a high percent of cpu is being used and by what application(s)?

Or might it be the IDE drive as you suggest. You might see a delay
when switching to a different shell window (as things are brought
back from swap space) are but then it seems to run pretty normal.

If something like a big dd or cat takes most of the cpu, on Solaris that
can be a quick and dirty indication that the IDE drive is not using DMA.

--
Jon H. LaBadie jon < at > jgcomp.com
JG Computing
4455 Province Line Road (609) 252-0159
Princeton, NJ 08540-4322 (609) 683-7220 (fax)

On Sun, 15 Feb 2004, Kirk Strauser wrote:

I use Amanda to backup an iMac running Mac OS X (10.2). The backup runs
perfectly, but the machine is horribly unresponsive while tar is running,
both during the estimate and dump stages. Renice'ing the tar processes
doesn't seem to help, so I'm guessing that it might be an IDE DMA thing,
although I don't know my way around Mac hardware well enough to know.

Has anyone else seen this, and hopefully found a way to lessen the impact?

Yes, we've seen it, too. Have not (yet) dug into it to try to figure
out what's going on. The machine we've noticed it on is a Powerbook.

-Mitch