Hi,
--On Donnerstag, 27. Mai 2004 19:54 Uhr +0100 Colin Bruce <[EMAIL PROTECTED]> wrote:
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.
we have seen similar problems using TSM (Tivoli Storage Manager) backup software. See also below.
--On Donnerstag, 27. Mai 2004 13:19 Uhr -0600 Michael Loftis <[EMAIL PROTECTED]> wrote:
Linux has a LOT of known problems with huge amounts of memory...try reducing your memsize to 3Gb or 4Gb either by physically pulling chips or memsize=<blah> on the boot line Lilo you can say something like 'linux memsize=4096M' in GRUB you have to use 'e' to edit one of the options, then scroll down to the line containing kernel.... and add memsize= to the end of it by 'e' editing that line, then you can use b to boot. See if that helps your performance.
This I can confirm. We have Dell 6450 systems with 8GB of RAM and the caching has caused us no end of problems. Recentyl we reduced the memory to 2 GB and things are better. However, now, after two years of problems we reported to Red Hat, they finally came up with a suggestion about how to tune the kernel, albeit somewhat vague: they recommended we lower the values in /proc/sys/vm/pagecache. On RH AS 2.1 they default to:
2 50 90
We have now reduced them to:
2 10 60
Hmm, I just noticed that the RH AS 3 values default to:
1 15 100
Things *seem* to be working better this way, but we'll have to see ...
Cheers, Sebastian Hagedorn -- Sebastian Hagedorn M.A. - RZKR-R1 (Gebäude 52), Zimmer 18 Zentrum für angewandte Informatik - Universitätsweiter Service RRZK Universität zu Köln / Cologne University - Tel. +49-221-478-5587
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