On Fri, Apr 11, 2008 at 3:18 AM, Linux <linuxlist at gmail.com> wrote: > On Fri, Apr 11, 2008 at 2:43 AM, William L. Maltby > <CentOS4Bill at triad.rr.com> wrote: > > > > On Fri, 2008-04-11 at 02:02 +0300, Linux wrote: > > > On Fri, Apr 11, 2008 at 1:44 AM, Benjamin Karhan <simon at pop.psu.edu> wrote: > > > > ] Every 59 minutes (maybe every hour) it reboots without any logs, > > > > ] without any traces and unfortunately with breaking software raid. > > > > ] After reboot dmesg does not have any strange entries. > > > > this really only helps you if you have X11 installed/enabled to begin with... For the records... Thanks for your responses and here is feedback: - ssh root login is limited to certain ip's only... - reboot is definitely a "cold reboot" but I am not a native english speaker :) - power surge/temporary failure is not a case, datacenter has expensive power equipment - nor cpu heat is a case. I placed an extra thermometer and moved server to the frond of cold air inlet. - lmsensors or sensors does not exists. - I tested with/out crons before. Pretty sure no relation with crons. - External and internal services were expected to leave some marks. Did a cronned "ps ax" and checked processes that run before restart, nothing suspicious. Consequently: I had 4 DDR ECC RAM modules each 2 GB paired in 2 different brands. Each brand functioned well as 4GB total but when all are installed nightmare begins. I guess (this time a real guess) I have a problem with my RAM settings. 8 GB may cause this problem, may be a serious page fault etc... Without grub parameter "mem=" server boots very slowly and also responses very slowly. Maybe I need a new thread title "Server too slow or too unstable with 8 GB RAM" :) Thanks...