Host: Windows Server 2003 (H/w: 2x Quad Core Xeon Processors)
VirtualBox 4.2.x (don't remember the exact version)
Guest (i'll refer to this as the server): Debian Squeeze/Stable, (32-bit, 2 Cores, 2GB RAM, 160GB Dynamically allocated vdi disk)

The Debian Guest currently runs Syslog-ng server, Logstash with embedded ElasticSearch and Kibana. The load figures are high, it varies between 4-12 (past minute figures). CPU usage is usually above 100% (as per top), when some of the services are being restarted it even goes above 200% with load going upto 12.

This server keeps losing time, the server's system time slows down by about 3-4 hours during the course of the day. Could it be because the server is so overloaded?

I have tried running the ntp daemon on it with the default configuration, it hasn't helped. Shouldn't it be able to keep time without NTP?

What could be causing this?

thanks in advance

I remember a long time ago this was an issue for various things. 3-4 hours a day is way too much. I doubt (well maybe could be) it could be load. It used to be there was some setting to use or not use system time on the some of the VM's. Cron to ntp may help until you get this figured out. For me, it has remained rock solid for time.

This is the Vbox doc's link if it will help. http://www.virtualbox.org/manual/ch09.html#idp14894848