My Linode stops responding sometimes
My Linode 1024 sometimes stops responding. When it happens, everything stops, i.e., web, ssh, ftp etc. This has happened twice since I did a fresh install of Ubuntu 10.04 LTS. Both times, rebooting from the control panel got it going again.
This is a LAMP server running Drupal and OpenX.
Any ideas on what might be happening? What logs etc should I be looking at for further info?
It happened this morning. It was an hour or so before I knew about it. I guess I need to setup some sort of monitoring. I noticed that when I told it to reboot, the control panel took about 5 minutes to complete which is much longer than normal.
Thanks
2 Replies
@tetranz:
I don't think I had enough swap space. I've increased it to same as memory size.
If your Linode has to use swap for anything other than clearing processes that execute very infrequently out of RAM to make room for more cache, it will slow to a crawl. The symptoms you describe are typical of swap thrashing, where the machine spends all its time moving processes that are actually trying to execute in and out of swap. Check the many threads on this forum for advice on how to tune Apache and MySQL to work within the available RAM. Many default configurations of Apache assume that you have multiple GB of RAM available (as is the case on a physical server) and they need to be altered to work properly on a VPS with limited memory.