- Plesk for Linux
The DNS service goes down when the system is low on memory (RAM):
# free -h
total used free shared buff/cache available
Mem: 1.6G 1.1G 18M 81M 492M 367M
Swap: 1.0G 992M 31M
journalctl -u named-chrootcommand shows that the DNS process was killed:
CONFIG_TEXT: systemd: named-chroot.service: main process exited, code=killed, status=9/KILL
sh: kill [options] <pid|name> [...]
sh: For more details see kill(1).
systemd: named-chroot.service: control process exited, code=exited status=1
systemd: Unit named-chroot.service entered failed state.
systemd: named-chroot.service failed.
The following message appears in
# grep -ir kernel /var/log/messages | grep Kill
kernel: Out of memory: Kill process 3505 (named) score 8 or sacrifice child
The DNS service is getting killed by OOM Killer due to critically low memory on the system.
Allocate additional memory (RAM) to the server.
Check server health to find out if memory usage is expected.
For example, memory is used by some extremely popular website or there is a memory leak in a web app or somewhere else. Use the atop utility for this purpose.