Why is my cron daemon is being killed every few minutes?
- by user113215
As of about a week ago, my cron daemon refuses to stay running. I'm using Debian 6 x64 on an OpenVZ virtual machine. Running something like pgrep cron shows that the daemon isn't running. I start the service with service cron start or /etc/init.d/cron start and it launches, but it disappears from the running process list after a few minutes (varying anywhere between 1 - 30 minutes before the process is killed again).
Using strace -f service cron start, I can see that the process is being killed for some reason:
nanosleep({60, 0}, <unfinished ...>
+++ killed by SIGKILL +++
There's nothing relevant in /var/log/syslog, /var/log/messages, /var/log/auth.log, or /var/log/kern.log to explain why the the process is dying. The system has at least 800 MB of free memory, and cat /proc/loadavg returns 0.22 0.13 0.04 so resources shouldn't be the issue. With cron running, free -m reports:
total used free shared buffers cached
Mem: 1024 211 812 0 0 0
-/+ buffers/cache: 211 812
Swap: 0 0 0
I also tried removing and reinstalling the cron package using apt-get.
Update: I initially thought the problem was a resource issues. I erased my entire VPS and started from a fresh Debian image. There is now nothing else running on the system, but even from a clean install my cron daemon is still being killed at random.
What else should I check? How do I find out what's killing my crond?
