Unplanned reboots

[username]

Hi,

I have a CentOS 7 server that is doing some unplanned reboots :

reboot system boot 3.10.0-957.21.3. Sun Jul 28 07:04 - 13:19 (1+06:14)
reboot system boot 3.10.0-957.21.3. Sun Jul 28 06:22 - 13:19 (1+06:56)
reboot system boot 3.10.0-957.21.3. Sun Jul 28 06:16 - 13:19 (1+07:02)

reboot system boot 3.10.0-957.21.3. Fri Jul 19 05:00 - 13:19 (10+08:18)
reboot system boot 3.10.0-957.21.3. Fri Jul 19 04:58 - 13:19 (10+08:21)
reboot system boot 3.10.0-957.21.3. Fri Jul 19 04:55 - 13:19 (10+08:24)
reboot system boot 3.10.0-957.21.3. Fri Jul 19 04:41 - 13:19 (10+08:38)
reboot system boot 3.10.0-957.21.3. Fri Jul 19 04:31 - 13:19 (10+08:47)
reboot system boot 3.10.0-957.21.3. Fri Jul 19 04:01 - 13:19 (10+09:18)

I have nothing scheduled in my crontab at this time.

I don't see any info about the reboots in /var/log/messages. It all seems very sudden (an electrical reboot ?) :

Code: Select all

Jul 28 06:11:01 extranet3 systemd: Created slice User Slice of root.
Jul 28 06:11:01 extranet3 systemd: Started Session 13472 of user root.
Jul 28 06:11:01 extranet3 systemd: Removed slice User Slice of root.
Jul 28 06:12:01 extranet3 systemd: Created slice User Slice of root.
Jul 28 06:12:01 extranet3 systemd: Started Session 13473 of user root.
Jul 28 06:12:01 extranet3 systemd: Removed slice User Slice of root.
Jul 28 06:13:01 extranet3 systemd: Created slice User Slice of root.
Jul 28 06:13:01 extranet3 systemd: Started Session 13474 of user root.
Jul 28 06:13:01 extranet3 systemd: Removed slice User Slice of root.
Jul 28 06:14:01 extranet3 systemd: Created slice User Slice of root.
Jul 28 06:14:01 extranet3 systemd: Started Session 13475 of user root.
Jul 28 06:14:01 extranet3 systemd: Removed slice User Slice of root.
### Some non-UTF8 chars here ###
Jul 28 06:16:48 extranet3 kernel: Initializing cgroup subsys cpuset
Jul 28 06:16:48 extranet3 kernel: Initializing cgroup subsys cpu
Jul 28 06:16:48 extranet3 kernel: Initializing cgroup subsys cpuacct
Jul 28 06:16:48 extranet3 kernel: Linux version 3.10.0-957.21.3.el7.x86_64 (mockbuild@kbuilder.bsys.centos.org) (gcc version 4.8.5 20150623 (Red Hat 4.8.5-36) (GCC) ) #1 SMP Tue Jun 18 16:35:19 UTC 2019
Jul 28 06:16:48 extranet3 kernel: Command line: BOOT_IMAGE=/boot/vmlinuz-3.10.0-957.21.3.el7.x86_64 root=/dev/md2 ro crashkernel=auto rhgb quiet rd.md.uuid=1f9f6320:782b2777:a4d2adc2:26fd5302 rootdelay=10 rootdelay=10 noquiet nosplash net.ifnames=0 biosdevname=0 LANG=en_US.UTF-8

[username]

Is there another log file that could be useful to get more information about what causes these reboot ?

I have sent an email to the server provider to make sure it isn't an hardware issue.

[TrevorH]

### Some non-UTF8 chars here ###

You mean random binary data? That's an indication that your server died and left the filesystem unclean with data pending to be written. Most likely you have a hardware problem causing the server to reboot like that. It could also be a kernel panic but the lack of any useful info in /var/log/messages and the presence of residual data in that file point more to something like a power problem.

[username]

### Some non-UTF8 chars here ###

You mean random binary data?

Yes, it seems so. When I open the log with Vi I can see a very long line of ^@^@^@^@^@^@^@^@^@^@^ right before every reboot.

When I opened it on my desktop with Kate I was warned that the file contained invalid characters and could only be opened in read-only mode. If i delete the ligne of ^@^@^@^, I can open and save the file normally.