I'm trying to run monerod on a VPS and after several minutes of working correctly the program just stops. There are no logs which indicate any errors or warnings in .bitmonero/bitmonero.log even with log-level 4. I've tried to go through my system logs and there's nothing I can find that indicates what is happening either. The only hints I have is sometimes I get the following message when running "./monerod status" right before the moment it crashes:
bash: fork: Cannot allocate memory
It seems pretty straightforward that there's a memory problem, but there are no logs indicating this or the cause. Ulimit reveals that each process can use unlimited virtual memory, so that's not the problem. I have 3 GB of ram and 2 GB of swap space. When running top or htop neither indicate that much memory is being used at all. The df tool shows that I have 23GB of hard drive space remaining, as well, so it's not as if I've run out of storage. The free tool suggests that I have about 4 GB of memory available even when monerod is running before it crashes. I've updated my operating system and restarted it with no changes in behavior. Changing the number of threads spawned and input/output connections can change the timing but ultimately monerod will still fail. On this VPS I don't have access to logs like /var/log/kern.log, unfortunately.
If it helps, I'm using Ubuntu 16.04.4 LTS.
Anyway, I've really exhausted every option I could find. None of the logs available seems to indicate that there is anything that is failing. This problem is stopping me from running a monero node altogether.