[CentOS] Random server reboot after update to CentOS 5.3

Dear ML

We upgraded a Dell Poweredge PE 1950 Server the 8th of May. Since then 
the server rebooted 3 times without external cause (it is located in a 
server farm with redundant power supply etc.). Looking at the servers 
monitoring infrastructure with Dell's own OpenManage tools, I  get 
strange errors:

 [root at servernew ~]# omreport system esmlog

(....)

Severity      : Critical
Date and Time : Mon May 11 17:46:59 2009
Description   : System Software event: run-time critical stop was asserted

Severity      : Critical
Date and Time : Fri May 15 21:07:57 2009
Description   : System Software event: run-time critical stop was asserted

Severity      : Critical
Date and Time : Wed May 20 21:00:53 2009
Description   : System Software event: run-time critical stop was asserted


(...)

This class of errors never happened before in over a year that the 
server is running.

There is no mention of any anomaly, except the boot messages itself, in 
/var/log/messages.

The server runs the 64 bit flavor of CentOS hosting some XEN virtual 
machines and some PostgreSQL and MySQL databases. It run without any 
issues with CentOS 5.1 and 5.2.

I interpreted these issues as some kernel/software related problem, but 
do not know how to make a more accurate diagnosis of the problem.

Can anybody give me some hint? Has anybody had some similar issue?

Regards,

Peter

-- 
 
Dott. Peter Hopfgartner
 
R3 GIS Srl - GmbH
Via Johann Kravogl-Str. 2
I-39012 Meran/Merano (BZ)
Email: peter.hopfgartner at r3-gis.com
Tel. : +39 0473 494949
Fax  : +39 0473 069902
www  : http://www.r3-gis.com