slowdown/swapping unresponsiveness

[jwilke]

Hi all,

Lately I have been running into a nasty problem: occasionally my zimbra server
(ubuntu dapper 32bit 6gb mem qc3,2ghz) is grinding to a halt, where a java process is taking up 50%cpu and about 30% memory. (load jumps up to 11)

Zimbra becomes generally unresponsive, and vmstat show heavy swap activity. occasionally this goes away by itself, but sometimes it requires a zimbra restart.

Immediately after I do the restart things are back to normal.

I've already changed my server configuration to accommodate for most of the tweaks listed in the performance wiki, except for any changes to mailboxd heap size and mysql_memory_percent. I did try to change vm.swappines to 0, but this resulted in oom_killer whacking java processes which is undesirable

Is there any way to visualise what exactly the java processes are doing so I can get a better idea of what is going wrong ?

Regards

Jeroen

[iway]

See: Sudden Zimbra slowness?
And: Zimbra on Ubuntu 8.0.4 - severe issues