Comment 8 for bug 494476

I have (quiet) the same issue twice in 2 days (on karmic)

But I am not using ext4 (only ext3 and jfs)

and the first crash I had, it was trackerd the first blocking task :
(from kern.log)
Apr 19 11:28:43 localhost kernel: [156600.910099] INFO: task trackerd:3486 blocked for more than 120 seconds.
(full kern.log on demand)

The second time it was cron (but I didn't check if the ran script was IO consuming or not)
(from kern.log)
Apr 20 14:20:59 localhost kernel: [68160.710147] INFO: task cron:28148 blocked for more than 120 seconds.
(log of Apr 20 seems to be polluted by the systReq I misused)

No "strange" update the last days, but I enabled a new django site the day before the first crash (in debug mode) => maybe memory whore.

For my specific case (may be different than the one reported here) I suspect 2 causes :
   * hardware failure.
   * or bad behavior of something in case of (low memory + huge IO activity.)