CentOS vps is randomly rebooting

Question

I have a centos vps (Parallels Virtuozzo container) which has been running for months. However, a few days ago it started to randomly reboot itself, and i can't find out why. And the biggest problem that i don't understand is that it takes 40 minutes to reboot (as far as i can see in the logs)

root ~ # cat /var/log/messages | grep shutdown
Oct 11 13:52:11 vps27 shutdown[23968]: shutting down for system halt
Oct 14 14:55:17 vps27 shutdown[30662]: shutting down for system halt
Oct 15 06:21:23 vps27 shutdown[20157]: shutting down for system halt

And notice the time difference between shutdown and xinetd's start:

Oct 15 06:21:23 vps27 shutdown[20157]: shutting down for system halt
Oct 15 06:21:24 vps27 init: Switching to runlevel: 0
Oct 15 06:21:27 vps27 saslauthd[30614]: server_exit     : master exited: 30614
Oct 15 06:21:38 vps27 named[30661]: shutting down
Oct 15 06:21:47 vps27 exiting on signal 15
Oct 15 07:04:34 vps27 syslogd 1.4.1: restart.
Oct 15 07:05:06 vps27 xinetd[1471]: xinetd Version 2.3.14 started with libwrap loadavg labeled-networking options compiled in.
Oct 15 07:05:06 vps27 xinetd[1471]: Started working: 0 available services

And here's what Parallels Power Panel says in terms of Status Changes:

Time                       Old Status          Status Obtained
Oct 15, 2011 06:23:46 AM    Mounted                Down
Oct 15, 2011 06:22:31 AM    Running                Mounted
Oct 14, 2011 03:06:48 PM    Starting               Running
Oct 14, 2011 03:06:23 PM    Down                   Starting
Oct 14, 2011 03:06:08 PM    Mounted                Down
Oct 14, 2011 02:58:24 PM    Running                Mounted

For some reason it's getting into Mounting mode and then restarts itself.

The only problem that i can imagine is disk space utilization, which is now 84%. But can that be a reson for system halt?

Time    Category    Details Type    Parameter
Oct 15, 2011 07:08:33 AM    Resource    Resource counter_disk_share_used yellow alert on environment vps27 current value: 82 soft limit: 85 hard limit: 95  Yellow zone counter_disk_share_used
Oct 15, 2011 06:27:23 AM    Resource    Resource counter_disk_share_used yellow alert on environment vps27 current value: 82 soft limit: 85 hard limit: 95  Yellow zone counter_disk_share_used
Oct 15, 2011 06:23:50 AM    Resource    Resource counter_disk_share_used green alert on environment vps27 current value: 0 soft limit: hard limit: 0    Green zone  counter_disk_share_used
Oct 14, 2011 03:06:24 PM    Resource    Resource counter_disk_share_used yellow alert on environment vps27 current value: 83 soft limit: 85 hard limit: 95  Yellow zone counter_disk_share_used
Oct 14, 2011 03:05:50 PM    Resource    Resource counter_disk_share_used green alert on environment vps27 current value: 0 soft limit: hard limit: 0    Green zone  counter_disk_share_used

Answer 1

Disk space would not cause the system to halt (unless perhaps Parallels Virtuozzo is imposing this due to hitting quota, which seems unlikely).

• are you short of RAM? Try running free -m and paste the output here. Low RAM is a reasons for very slow bootup and operation.
• run top in a terminal and keep it open until the next restart - best to have two windows, one sorted by CPU and one sorted by memory.

Really you need to log a ticket with your web host as they are best placed to diagnose and fix this, and it may be specific to your environment.

Answer 2

I am not sure if you are hosting this vps on your own hardware or someone elses, but if you the server has really high disk usage your server trying to boot maybe having to wait to start loading the os. But for the random shutdown try to find out which user is causing the shutdowns and then see if you have a kiddie script somewhere.