how to optimize CentOS XEN dom0?


I have a problematic CentOS XEN server and hope someone could point me in the right direction to optimize it a bit.

The server runs on a Core2Quad 9300, with 8GB RAM (max motherboard can take, 1U chassis) on an Intel motherboard with a 1TB SATA HDD.

dom0 is set to 512MB limit with a few small XEM VM’s running:

root@zaxen01:[~]$ xm list Name ID Mem(MiB) VCPUs State Time(s) Domain-0 0 512 4 r----- 96.5 actionco.vm 3 1519 1 -b---- 14.8 byracers.vm 4 511 1 -b---- 85.7 ns1 5 511 1 -b---- 22.3 picturestravel 6 255 1 -b---- 13.3 rafttheworld 7 255 1 -b---- 11.3 zafepres.vm 8 511 1 -b---- 19.0

the server itself seems to eat up a lot of resources:

root@zaxen01:[~]$ free -m total used free shared buffers cached Mem: 512 472 39 0 13 215 -/+ buffers/cache: 244 268 Swap: 4095 0 4095

Yet, it only has XEN, Webmin (since it’s a CloudMin XEN server), Exim, Apache and a few other services running:

root@zaxen01:[~]$ chkconfig --list |grep "3:on" |awk '{print $1}' |sort acpid auditd crond csf dhcpd exim haldaemon httpd iptables iscsi iscsid kudzu lfd lvm2-monitor mdmonitor network qemu restorecond setroubleshoot smartd snmpd sshd syslog sysstat webmin xend xendomains

Is there anything I can optimize on such a server?

Its a linux server - it’s going to use all the available ram if it does any I/O at all. I assume it’s the memory use that’s bothering you? Though my question would be why would you be running httpd and mail on the dom0 server? If you’re not using iscsi you could turn those off as well.

I posted the question cause the server keeps running our of memory, and those stats were posted a few minutes after it was hard rebooted. It simply didn’t respond to SSH, Webmin login or on the console.

It runs HTTPD & Exim cause it’s a CloudMin XEN host node