Subject: Re: High interrupt CPU usage with amanda backup on a SPARCclassic
To: Hauke Fath <hauke@Espresso.Rhein-Neckar.DE>
From: Francis Devereux <>
List: port-sparc
Date: 02/08/2003 20:57:36
> At 21:55 Uhr +0000 6.2.2003, Francis Devereux wrote:
> >I have a SPARCclassic that I am using as an amanda backup server.  It has an
> >external 1GB SCSI disk and HP C1537A DDS-3 tape drive.  It is running NetBSD
> >1.6.
> What is the nominal throughput of that DDS-3 streamer?

It used to do about 1 megabyte per second when it was hooked up to a faster
machine (unfortunately I haven't been able to get anything other than Solaris
to run well on that machine, it's based on a SPARCengine Ultra AXi, I think I
made a post to port-sparc64 about it a while ago but didn't get anywhere).
It does about half that on the SPARCclassic.

> Do you run it with HW compression enabled or not (you should not)?

I think that I was using HW compression, I'll try turning it off.

> >When the amanda is backing up over the network the CPU usage is very high
> >(see top output below), mainly interrupt and system,
> Did you set up Amanda with client-side or server-side compression?


> >and the tape keeps stopping and starting. Is this normal, or is there any
> >way I can make the backup go faster?
> Do you use a holding disk in your setup (you should)? What size?

No, but I have a spare 1GB disk I will try.  Unfortunately some of the
filesystems I'm backing up are much bigger than that.

Thanks for the suggestions,