Ubuntu 11.10 Shutting Down Randomly and Unexpectadely

Question

I have a bit of a strange problem that just started happening recently. Out of nowhere Ubuntu 11.10 will just shut down.

I don't think its hardware because I can't find any information in the logs. I don't think its temperature because I monitor my temps and my machine is liquid cooled. The pc continues to run while the OS shuts down so its not being interrupted by power where all of a sudden everything just loses power. I don't really overload the machine at all, I mostly just code on it, but I do have apache2, tomcat, james email server, and mysql running on the system and they are auto started. I don't actually have any traffic coming into the machine though, I use it specifically for development.

Edit from comments:

It's not really going to a shut down screen, the screens go black and the computer still runs, but the actual OS shuts down because if I'm listening to music or something, the music will skip a few times and then stop. This is how Ubuntu normally shuts down for me so I assume its a software shutdown. It's not following a pattern unfortunately, it's random and sometimes within a few hours of the last time, other times its days between. Normally when I am on the machine.

Any ideas on how I can diagnose a problem like this? Does this sound like a memory leak issue?

Answer 1

Can you check the following and update your question with more information on it:

• Ubuntu - Power Management Features (Shutdown on idle or Sleep on idle)
• Ubuntu - Cron jobs for root and other users
• Ubuntu - Recent Updates (Some updates require system reboot - I assume auto updates would restart the system when required)
• BIOS - Power Management (enabled or disabled)
• BIOS - Recent Updates
• APPS - Any Bit torrents running? (Some Bit torrents shutdown after complete if set) - as seen in this forum

To check the cronjob type the following in the terminal:

for active session (the account you logged in with) cron jobs

crontab -l

for root's cron jobs

sudo crontab -l

for any other user's cronjob

sudo crontab -u <usename> -l

Answer 2

In general in a situation like this where you have an error that is hard to pinpoint and only happens from time to time you can only use the process of elimination to find the error. The first and obvious thing to try reseting the software part of your computer, so you could try backing up all your stuff and do a completely fresh install of 12.04 and see if the problem persists.

If it does, it might be hardware related. You can run a memory test which is included on all Ubuntu boot media overnight, if that turns out clean it might be any piece of hardware in your computer. It might be the PSU, the motherboard, your graphic card and so on. The only way to know for sure is replacing one at a time.

Answer 3

That does not sound like a memory leak - that would just lead to poor performance rather than a sudden shutdown.

Does it happen at a specific time? If you are seeing a shutdown screen rather than just losing power, then it seems likely that an auto-shutdown script is running somewhere. Check this question for more details on that:

Why does my computer shuts down itself every morning at 6 AM?

Answer 4

Turns out the problem was the video card either being faulty, or more likely overheating. I replaced the card with a spare I had and its working fine. I didn't realize how loud the fan on the card was until I removed it, and it was completely saturated with dust. Gonna clean it out real good and try it again, but that was the culprit. How dare I blame Ubuntu! :)