Comment 612 for bug 993187

I have seen this happen 3 times in the last 2 days since I installed 12.04.1-desktop-amd64 on my core i5 p8z77-v pro. Kernel is 3.2.0-35-generic and everything was brought up to date via update manager.

The system is totally frozen: I can't even ping it from my laptop and I've verified the correct IP from the my router and the mac address of the frozen system. I was able to ping it before. Perhaps even more interesting, when I hit the hard reset button, nothing immediately happens! I don't know how this is implemented, but in the past I've always got an immediate reset. I hit it 2 or 3 times, and it was perhaps 10 seconds later I got a reset. The last time it froze, I saw the same thing, but I didn't as long prior to trying the power button. A single press of the power button did nothing, and I had to hold it down to get the system to reset (as expected.)

I was previously running 12.04.1-desktop-i386 on the same machine with identical setup and did NOT see any problems in the same amount of time. Not a definitive finding, I know, as the time frame is quite short, but I perhaps spent more time on the 32-bit version than I have so far on the 64-bit.

The syslog doesn't show anything prior to the reboot, although it looked like cron would have just been running: the previous log was at 19:17:01 so the next hourly would have been 20:17:01 and and my reboot was started at 20:19:18. I was browsing the web with firefox 17.0.1 when it froze up. Nothing else going on that I can recall. The previous freeze, I can' t recall if I was browsing, but I was running filezilla to transfer a large directory from a local computer allowing 10 open sftp connetions. After rebooting, I did the same operation 3 or 4 times again without a problem. That was approximately 24 hours ago.

Not sure what else to look for. I don't really know my way around linux that well, so if someone wants me to look at something the next time this hangs (and I'm sure it will within another 24 hours or so) just let me know.

Otherwise, at some point, I'll may try to upgrade the kernel. I've never done so and don't know what the current state of affairs is, so I guess I'll have to do some research first.

Brian

Oh, I'll also run a memory test overnight. I've got 16g running at 1600 using an XMP profile, but otherwise, I'm not overclocked. Also, not using swap. I do have an SSD as my main system disk and have mounted /var and /home from an internal RAID5 array with /tmp, /var/tmp and /var/spool using tmpfs. Also, using deadline on the SSD (via rc.local) and leaving all other devices NCQ. The only other thing I've changed from stock is I've mounted the SSD with noatime, notdiratime and discard. Everything is ext4. The only other device I have mounted is an ntfs partition from another drive, but wasn't accessing anything at the time. Oh, and my browser cache is set to memory. I think that covers it. All of this was also my configuration when previously running 32bit.