Epilogue: I've tried to disable TSO (ethtool -K eth0 tso off), as was suggested on the poweredge list. This did not help. I've configured the machine to start with the 5.2 kernel in /boot/grub/grub.conf, changing the default. It has been running for 6 1/2 days, now. I would say that this helped and is what I would suggest to others experiencing the same problem, right now. Thus, current running kernel is 2.6.18-92.1.10.el5xen. Regards and thanks for all replies, Peter Peter Hopfgartner wrote: > 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