[mythtv] [mythtv-commits] Ticket #2335: LiveTV hangs when a recording is finished and a new on starts (no channel change)

Willy Boyd willyboyd at gmail.com
Wed Apr 4 15:48:01 UTC 2007

On 4/3/07, MythTV <mythtv at cvs.mythtv.org> wrote:
> #2335: LiveTV hangs when a recording is finished and a new on starts (no channel
> change)
> -----------------------------------------+----------------------------------
>  Reporter:  tino.keitel+mythtv at tikei.de  |        Owner:  ijr
>      Type:  defect                       |       Status:  reopened
>  Priority:  minor                        |    Milestone:  unknown
> Component:  mythtv                       |      Version:  head
>  Severity:  medium                       |   Resolution:
> -----------------------------------------+----------------------------------
> Comment(by anonymous):
>  I have been chasing this "bug/feature" for about the past 3 months now
>  with Fedora 6 and MythTV .20. I tried all the tricks that I knew about
>  tweaking linux, i.e. hdparm, setpci, turn off all services(yea thats
>  right, I turned off everything except mysqld and lircd), and a couple of
>  other things. I even tried different hardware. All to no avail. I finally
>  camne across this post http://www.gossamer-
>  threads.com/lists/mythtv/users/258531 where they discuss tuning mysql. I
>  started with the settings below for my /etc/my.cnf file.
>  old_passwords=1
>  key_buffer = 16M
>  max_allowed_packet = 8M
>  table_cache = 128
>  sort_buffer_size = 16M
>  net_buffer_length = 8M
>  thread_cache_size = 4
>  query_cache_type = 1
>  query_cache_size = 4M

I'm the original poster of that thread.  I'm glad it helped; like you,
I tried all kinds of things before stumbling upon the tuning tips
above.  To be honest I was quite pleasantly shocked that that alone
cured my freezing issues with SD.

>  This did improve the freezing slightly. It still froze during the night
>  when it ran mythfilldatabase. So I did a little research on tuning mysql
>  myself(there is alot of stuff to look at so I didn't really learn that
>  much). However I eneded up with a /etc/my.cnf that looks like this in th
>  mysqld section.
>  old_passwords=1
>  key_buffer = 32M
>  max_allowed_packet = 16M
>  table_cache = 1000
>  sort_buffer_size = 32M
>  net_buffer_length = 16M
>  thread_cache_size = 200
>  query_cache_type = 1
>  query_cache_size = 24M

Thank you for the updated settings!  I just got my HDHomeRun a couple
nights ago, an experienced a freeze on program change (myth wanted to
record House so I chose to watch and record, and it hung).  I'm
assuming it was because of the extra performance needed for HD since
the basic tuning cleared up things for SD, so I'm really hoping the
above changes help.  I'm updating my server now and I'll watch some TV
tonight and find out!  :)

It's been said before that putting the database on a different disk or
machine is a good idea, but I just currently don't have the setup for
it or else I might have tried that before even finding the tune up
settings.  But if changing the config alone is enough I say that's an
acceptable win (even if temporary).

>  And since I started using these settings I have not had a single freeze up
>  at any time, or any other issue for that matter. As soon as I went a day
>  without a freeze I did a complete reinstall of Fedora core 6 and Mythtv
>  .20 and used the new settings for mysql server. IT WORKS FLAWLESSLY :) :)
>  :). By the way, I am now using a E-Machines P4 2.6 Ghz with 768 MB of ram
>  and 2 PVR-150. When I first started, I was using one PVR-150 and one
>  WinTV-GO. I eventully gave up on the WinTV-GO card thinking that it was
>  causing some of the problem, but now that I have gone about a week and a
>  half without any issues(no reboots), I'm starting to think about trying
>  the WinTV-GO card again. The bottom line is that it was deffintly the
>  mysql server performance that was causing this problem for me and I bet
>  for alot of other people as well. I hope the developers see this and can
>  help get it right in upcomming releases. If you run mythbackend with the
>  "-v all" option you will see that myth is doing ALOT and I do mean ALOT of
>  sql queeries for seek positions.
> --
> Ticket URL: <http://svn.mythtv.org/trac/ticket/2335#comment:33>
> MythTV <http://svn.mythtv.org/trac>
> MythTV
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