[mythtv-users] mythfilldatabase problems

Gary Buhrmaster gary.buhrmaster at gmail.com
Fri Sep 9 20:12:42 UTC 2011

On Fri, Sep 9, 2011 at 19:56, mythtv at blandford.net <mythtv at blandford.net> wrote:
> The disk I/O is quite high while mythfilldatabase is running.  atop
> shows the mirror with the database on it to be very busy.

And I would guess that this would likely to be the issue.

> I believe Dan ordered an SSD to work around the issue, but this seems
> like sort sort of incompatibility has crept up.  Unfortunately, I don't
> know if it is something in fedora 15 like the kernel, mysql, filesystem,
> etc or something in Mythtv.

F15 ships with a newer mysql version than F14, and it
is likely you upgraded your mysql too.  At least in my
experience the newer mysql runs most queries much
faster (I presume the optimizer was improved), but I
have never evaluated the mythfilldatabase times, but
as with any version change, your results will vary.

You might try to change the various mysql temporary
file values to minimize the file I/O for temp tables
(tmp_table_size and max_heap_table_size).  I seem
to recall this can be a win for some configurations
(if your system has sufficient ram).

And you might consider running the mysqltuner.pl script
to determine if other mysql changes would help.

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