I created a physical virtual machine Oracle Enterprise Linux Server release 5.6 on Oracle VM server release 2.2.1. This is a DELL PowerEdge R710 with 2 4-cores Intel Xeon E5620 CPUs and 96GB memories. And the OLE is the only guest on the host. The first 12 virtual CPUs, 0-11, out of the 16 total available vcpu are assigned to the virtual machine and this configuration worked for more than 2 years.
The guest hang this morning. The number of the online vcpus dropped from 12 to 1 (used xm list to show the information) and the guest did not response at all. None of the ping, ssh, ftp or the applications on the server were OK. Though I connected to the console using a vncviewer client, the console was black at all. Nothing can be observed from the guest. The host is OK.
I connect to the host, destroied the guest (the connected vncviewer was disconnected automatically too), restarted it and it works as expected. The number of the online vcpus is 12 now.
The exactly same happened in April last year too.
I searched the Internet but could not find anything similar. Because I don't have a support of the virtual server, this is the only place I can think of for help.
Did anyone meet this before? Any suggestion on how to solve this problem, or how to find out the reason?