I have a server which is co-located in a data centre. The server OS is Ubuntu 6 (Dapper Drake I think). On the server I have installed VMware Server 2, and I have several VMs running on the host. The VMs are all Windows Server 2003.
My problem is that when I get a remote desktop to any of the VMs, everything works fine for a few minutes, and then for no particular reason the VM slows down dramatically. Even the clock slows down so that it falls behind the real time. For example, 5 minutes real time can elapse, but the clock on the VM will only show 2 minutes elapsed.
When I look at SysInternals Process Explorer on the VM, there isn't any one process which seems to cause the slow down. Sometimes the Explorer process is using CPU, sometimes it's TextPad; occasionally the Interrupts or DCPs processes seem to be using a lot of CPU. But even when nothing is using excessive CPU or memory, the VM seems to be in slow motion. The clock slows down; when I switch between windows it can take 15-20 seconds to do so.
Any ideas as to what might be causing this? It happens on all the VMs, not just one of them.