[mythtv-users] Mythpreviewgen

Josu Lazkano josu.lazkano at gmail.com
Sun Oct 16 16:03:25 UTC 2011

2011/10/16 Taylor Ralph <taylor.ralph at gmail.com>:
> On Sun, Oct 16, 2011 at 7:10 AM, Josu Lazkano <josu.lazkano at gmail.com> wrote:
>> 2011/10/15 Taylor Ralph <taylor.ralph at gmail.com>:
>>> If you are running ext4 on the backend you can try disabling barriers.
>> Hello, I am using EXT3 on the system hard disk and XFS on the
>> recording disk, I must check some here?
> Those filesystem types are fine.
>> The system disk is a 2.5 160GB, here is all the software and the mysql server.
>>> On the the frontend I assume you are using VDPAU. In the case of VDPAU
>>> you can provide more video buffers by setting vdpaubuffersize=32 in
>>> the filter section of the video profile.  This will help the frontend
>>> handle longer periods of no data transfer.
>> I just configure the buffersize to 32, I have a laptop to run the
>> frontend without VDPAU and there is too little playback stops.
> If that doesn't help then remove the vdpaubuffersize option since it
> will consume large amounts of video memory
>>> One more thing to check is to make sure you are not running "VDPAU
>>> Advanced" playback profile since the ION can not handle Advanced 2X
>>> deinterlacing for HD material. You should run "VDPAU Normal".
>> On the ION backen/frontend I have this configuration on VDPAU:
>> VDPAU Slim:
>> http://dl.dropbox.com/u/1541853/vdpau/vdpau1.png
>> http://dl.dropbox.com/u/1541853/vdpau/vdpau2.png
>> http://dl.dropbox.com/u/1541853/vdpau/vdpau3.png
> You are using VDPAU Slim which should be fine.
>>> And make sure you are running the very latest code since an audio fix
>>> was recently committed that could trigger playback glitches.
>> Which is the fix? I am using debian.multimedia repository package:
>> http://debian-multimedia.org/dists/stable/main/binary-i386/package/mythtv.php
> Your packages are for the 0.24.1 release (June 2011) and doesn't
> contain anything committed since then. You need
> https://github.com/MythTV/mythtv/commit/35468d7d5ce5af18280c8753775e3b54f7ceaf40
> which was committed on Oct. 5th.
> I didn't realize you were playing back on a laptop. It's possible that
> your CPU is throttling and possibly slowing down your IO/memory
> performance. Could you try disabling anytype of CPU throttling and see
> if that helps? Also, please provide the graphics chipset and video
> memory you are using.
> Regards.
> --
> Taylor
> _______________________________________________
> mythtv-users mailing list
> mythtv-users at mythtv.org
> http://www.mythtv.org/mailman/listinfo/mythtv-users

Thanks Taylor, I am using a HTPC with Nvidia ION plataform as
frontend/backend, but I try the laptop to test the mythpreviewgen
pauses on it. I think it is not related to playback, because I use
different profiles on both frontends and there are little stops on
playback (Normal and VDPAU Slim profiles).

I will wait for the jyavenard fix to be pulled to the
debian-repository, I never compile the source of mythtv,  I always
just use repositories.

I am checking the mysql performance, I configure this way:

But there is no luck, then I try this script: http://mysqltuner.pl/mysqltuner.pl

This is the result:

$ ./mysqltuner.pl

 >>  MySQLTuner 1.2.0 - Major Hayden <major at mhtx.net>
 >>  Bug reports, feature requests, and downloads at http://mysqltuner.com/
 >>  Run with '--help' for additional options and output filtering
Please enter your MySQL administrative login: root
Please enter your MySQL administrative password:

-------- General Statistics --------------------------------------------------
[--] Skipped version check for MySQLTuner script
[OK] Currently running supported MySQL version 5.1.49-3
[!!] Switch to 64-bit OS - MySQL cannot currently use all of your RAM

-------- Storage Engine Statistics -------------------------------------------
[--] Status: +Archive -BDB -Federated +InnoDB -ISAM -NDBCluster
[--] Data in MyISAM tables: 63M (Tables: 180)
[--] Data in InnoDB tables: 48K (Tables: 3)
[!!] Total fragmented tables: 29

-------- Security Recommendations  -------------------------------------------
[OK] All database users have passwords assigned

-------- Performance Metrics -------------------------------------------------
[--] Up for: 4h 15m 35s (59K q [3.860 qps], 699 conn, TX: 29M, RX: 9M)
[--] Reads / Writes: 27% / 73%
[--] Total buffers: 78.0M global + 48.7M per thread (151 max threads)
[!!] Allocating > 2GB RAM on 32-bit systems can cause system instability
[!!] Maximum possible memory usage: 7.3G (244% of installed RAM)
[OK] Slow queries: 0% (0/59K)
[OK] Highest usage of available connections: 7% (11/151)
[OK] Key buffer size / total MyISAM indexes: 48.0M/43.0M
[OK] Key buffer hit rate: 99.3% (347K cached / 2K reads)
[OK] Query cache efficiency: 42.8% (9K cached / 22K selects)
[OK] Query cache prunes per day: 0
[OK] Sorts requiring temporary tables: 0% (0 temp sorts / 953 sorts)
[!!] Joins performed without indexes: 87
[OK] Temporary tables created on disk: 13% (173 on disk / 1K total)
[OK] Thread cache hit rate: 97% (17 created / 699 connections)
[!!] Table cache hit rate: 3% (128 open / 3K opened)
[OK] Open file limit used: 23% (241/1K)
[OK] Table locks acquired immediately: 99% (56K immediate / 56K locks)
[OK] InnoDB data size / buffer pool: 48.0K/8.0M

-------- Recommendations -----------------------------------------------------
General recommendations:
    Run OPTIMIZE TABLE to defragment tables for better performance
    MySQL started within last 24 hours - recommendations may be inaccurate
    Enable the slow query log to troubleshoot bad queries
    Adjust your join queries to always utilize indexes
    Increase table_cache gradually to avoid file descriptor limits
Variables to adjust:
  *** MySQL's maximum memory usage is dangerously high ***
  *** Add RAM before increasing MySQL buffer variables ***
    join_buffer_size (> 128.0K, or always use indexes with joins)
    table_cache (> 128)

Must I change some configuration on this?

Thanks for your great help. Best regards.

Josu Lazkano

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