Host restarts unexpectedly

Solution

• Run last reboot to retrieve and analyze logs at the relevant time.

• Check the /var/log/history.d/history log file at the relevant time to determine whether the host was restarted manually.

• Check the /var/log/message log file to determine whether hardware errors or out-of-memory (OOM) events occurred around the relevant time.

• Check the /var/crash/ directory for relevant error logs.

• Verify that the CPU C-state configuration is disabled on the host.

  Run cat /proc/cpuinfo | grep 'cpu MHz' | awk -F " " '{print $4}' to check the status. If all CPU frequencies are identical, C-state is disabled. Otherwise, the CPU may enter deep sleep, causing a system crash.

• Log in to the host IPMI out-of-band management page to check for hardware failure alerts.