Cyrus dies

[Colin Bruce]

On Thu, 27 May 2004, Rob Siemborski wrote:

> If even the console isn't responding to the enter key I'm hard pressed to
> believe that cyrus is at fault.

Dear Rob et al,

I have found out the cause of this problem but I don't know what the
solution is. The good news from your point of view is that it isn't
anything to do with Cyrus - its our backup software.

The backup cycle starts at 9PM and the problem we are experiencing starts
about 17 minutes later and finishes 20 minutes after that. The backup
is still running at that point and continues for another 30 minutes or
so. It didn't seem to be strongly related. However, I tried doing a manual
full backup and that didn't cause a problem so I tried a manual incremental
backup and that killed the server. I had top running at the time with 1 second
delays between updates but it froze. However, it was showing kswapd at the
top with 99% CPU time and bpkar second with 56%. When I killed the backup
the imap system continued happily.

I suspect that when the backup software is doing an incremental it builds
some sort of list of all the files on the system in memory and by some
means this causes it to lock solid. I don't know whether it is swapping
at the time but even that shouldn't cause it to lock the way it does. It
may be a problem with Linux I suppose.

We use Veritas Netbackup (DataCentre) so we can refer the problem to them.
This is not the first problem we have had with Veritas and I wish we had
bought something else. Ah well such is life.

Best wishes.....
Colin

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