[mythtv-users] mythtv hard lockup

[Yeechang Lee]

David Rees <drees76 at gmail.com> says:
> I'm upgrading the machine to FC6 now, I see that it likely won't
> help, but thanks for the hint.

As noted, upgrading did help me quite a bit on a relative basis.

Another clue: Tonight the hang occurred again on my
frontend/backend. However, I decided to
a) Wait a bit after emergency syncing with the magic SysRq key before
emergency read-only remounting and rebooting, and b) watch
/var/log/messages (from a superuser session I opened up ahead of time,
since no local-disk writes = no sudoing after the fact). Here's what I
saw:

Dec 20 21:08:14 bijou kernel: SysRq : Emergency Sync
Dec 20 21:08:16 bijou kernel: SysRq : Emergency Sync
Dec 20 21:08:55 bijou last message repeated 4 times
Dec 20 21:08:58 bijou kernel: Emergency Sync complete
Dec 20 21:09:34 bijou kernel: Emergency Sync complete

44 seconds before the first emergency sync is complete and 78 seconds
before the second? And, yes, the system did come back to life; heck,
through the whole time mythbackend kept recording away (to a local
RAID array that isn't the boot drive) with no gaps in the
recording. This experience has taught me that it's possible emergency
syncing really might be able to bring back the system more often than
in my experience so far if I am just a little bit more patient. Now,
if I could just figure out what the cause is in the first place.

-- 
Yeechang Lee <ylee at pobox.com> | +1 650 776 7763 | San Francisco CA US