Hello,

My server is rebooting frequently(4 to 5times a day) without any logs, can any one help me out to fined the cause for the unexpected reboots of the server.

reboot system boot 2.6.18-194.3.1.e Fri Feb 4 15:16 (00:-24)

[root@elastix log]# cat /etc/redhat-release
CentOS release 5.5 (Final)

[root@elastix log]# uname -a
Linux elastix 2.6.18-194.3.1.el5 #1 SMP Thu May 13 13:09:10 EDT 2010 i686 i686 i386 GNU/Linux

[root@elastix log]# tail -1000 /var/log/messages | grep -10 syslog
Feb 4 14:10:57 elastix snmpd[2840]: Connection from UDP: [172.25.2.15]:52445
Feb 4 14:11:03 elastix last message repeated 8 times
Feb 4 14:11:03 elastix snmpd[2840]: Connection from UDP: [172.25.2.15]:43668
Feb 4 14:11:03 elastix snmpd[2840]: Connection from UDP: [172.25.2.15]:52445
Feb 4 14:11:04 elastix snmpd[2840]: Connection from UDP: [172.25.2.15]:43668
Feb 4 14:11:04 elastix snmpd[2840]: Connection from UDP: [172.25.2.15]:52445
Feb 4 14:11:04 elastix snmpd[2840]: Connection from UDP: [172.25.2.15]:43668
Feb 4 14:11:07 elastix last message repeated 8 times
Feb 4 14:11:45 elastix snmpd[2840]: Connection from UDP: [172.25.2.15]:55864
Feb 4 14:11:45 elastix snmpd[2840]: Received SNMP packet(s) from UDP: [172.25.2.15]:55864
Feb 4 15:16:28 elastix syslogd 1.4.1: restart.
Feb 4 15:16:28 elastix kernel: klogd 1.4.1, log source = /proc/kmsg started.
Feb 4 15:16:28 elastix kernel: Linux version 2.6.18-194.3.1.el5 (mockbuild@builder10.centos.org) (gcc version 4.1.2 20080704 (Red Hat 4.1.2-48)) #1 SMP Thu May 13 13:09:10 EDT 2010
Feb 4 15:16:28 elastix kernel: BIOS-provided physical RAM map:
Feb 4 15:16:28 elastix kernel: BIOS-e820: 0000000000010000 - 000000000009c800 (usable)
Feb 4 15:16:28 elastix kernel: BIOS-e820: 000000000009c800 - 00000000000a0000 (reserved)
Feb 4 15:16:28 elastix kernel: BIOS-e820: 00000000000e0000 - 0000000000100000 (reserved)
Feb 4 15:16:28 elastix kernel: BIOS-e820: 0000000000100000 - 00000000cfe70000 (usable)
Feb 4 15:16:28 elastix kernel: BIOS-e820: 00000000cfe70000 - 00000000cfe7c000 (ACPI data)
Feb 4 15:16:28 elastix kernel: BIOS-e820: 00000000cfe7c000 - 00000000cfe7f000 (ACPI NVS)
Feb 4 15:16:28 elastix kernel: BIOS-e820: 00000000cfe7f000 - 00000000d0000000 (reserved)

-Chaitanya

It could be hardware related, some motherboard bios have hardware logging integrated in them, you could check there and see if there is anything of note. Also, there is an option on most motherboards to determine what happens when power is lost (power back up or stay off). Try configuring this to leave the server offline after a reboot, it might help determine weather some software is causing the restart or not.

Does this happen at the same time each day? If so, you may want to see if there are any cron jobs that run at these times that could be related.

There is no power problem for the server as it is located in Data center with multiple power backups and this doesn't happen at the same time each day. how can i check which is causing the reboot of server by using basic tools.