[mythtv-users] fixes branch: can't kill mythbackend

[Steven Adeff]

On Tue, Dec 2, 2008 at 9:45 AM, George Mari
<george_mythusers at mari1938.org> wrote:
> Steven Adeff wrote:
>> On Mon, Dec 1, 2008 at 9:09 PM, Steven Adeff <adeffs.mythtv at gmail.com> wrote:
>>> On Wed, Nov 19, 2008 at 9:07 AM, Steven Adeff <adeffs.mythtv at gmail.com> wrote:
>>>> On Wed, Nov 19, 2008 at 8:34 AM, George Mari
>>>> <george_mythusers at mari1938.org> wrote:
>>>>> Steven Adeff wrote:
>>>>>> lately mythbackend has gone rogue on me. it sits the computer at 100%
>>>>>> on the wa meter in top and doesn't respond to any of the frontends, as
>>>>>> well I can't kill -9 it, I *have* to reboot. I have no idea why it
>>>>>> gets like this or why it's only been lately that this happens, but
>>>>>> being that it forces me to reboot the computer manually I then have to
>>>>>> wait for my RAID array to resync which is not fun.
>>>>>>
>>>>>> anyone have any ideas?
>>>>>> thanks!
>>>>>>
>>>>> If it's 100% on wa, that means its waiting for some IO operation to
>>>>> complete.  Use lsof to see what files that PID has open.
>>>>>
>>>>> Any messages in /var/log/messages or the mythbackend log?
>>>>>
>>>>> Does it only happen while it's recording, or playing back, or doing
>>>>> nothing, all of the above?
>>>> Ah, I tried fuser but did not think of using lsof... damnit.
>>>>
>>>> I can't tell what it's doing other than it stops writing to the log
>>>> and puts a lock on my RAID array such that I can't stop it. I have not
>>>> noticed it happen during playback, so far it has only occured when no
>>>> frontend is streaming anything (they may be on, but just at a menu),
>>>> and at least the last few times mythcommflag had two processes running
>>>> (which is what I have it capped to).
>>>>
>>>> I'll try lsof next time it happens. If it is a file operation on the
>>>> RAID array, is there a way to see why it cannot complete the IO
>>>> operation?
>>>>
>>>> thanks!
>>>
>>> ok, finally occurred again, I can't open the log since it's on the
>>> same RAID array as I seem to be having problems with.
>>> I did run lsof and have a huge list, but don't really know what I'm looking for?
>>>
>>> Thanks for the help!
>>
>> on a whim I "looked" at all the files being accessed on the RAID array
>> and it turns out I can't even do an 'ls' of the log directory which
>> makes me thing perhaps it could be myth having an issue writing to the
>> log file? perhaps its having an issue with the log rolling over?
>>
>> Thanks!
>
> I ran into the exact same problem over the last couple of weeks on a
> different machine I have with a RAID5 array, and I think it was the
> kernel.  I was in the process of yum upgrading from FC6 to FC9, and left
>   the machine on FC7 for a while.  It was during these few days that it
> was on FC7 that I noticed the RAID5 array just hanging every once in a
> while, when it was being accessed.
>
> I ended up going to FC8, then FC9, and the problem went away.
>
> But I had the exact same symptoms - any process accessing the array just
> hung - couldn't even do a directory listing, couldn't even shutdown the
> machine cleanly, which ended up in needing to re-sync the array upon
> re-boot.
>
> You may want to see what version of the kernel you are on, and see if
> there is a newer one available for your distro.

You know, I thought about that since I've just upgraded both my linux
frontends to Mythbuntu 8.10 (The two girls I live with both have
powerbooks and run Myth on those which would be the only other
frontends in the house). My backend is an older setup and still
running 2.6.24-15-generic. What I don't get is why it went months and
months with no issue and just started recently.

dist-upgrade time. fingers crossed =)

-- 
Steve
http://www.jobs-khakis-chicks.com/MythTV/
Before you ask, read the FAQ!
http://www.mythtv.org/wiki/index.php/Frequently_Asked_Questions
then search the Wiki, and this list,
http://www.gossamer-threads.com/lists/mythtv/
Mailinglist etiquette -
http://www.mythtv.org/wiki/index.php/Mailing_List_etiquette