[mythtv-users] mysql filling up hard drive

[Simon Hobson]

Dan Wilga <mythtv-users2 at dwilga-linux1.amherst.edu> wrote:

> If you have not already tuned MySQL, you should look into the settings available in /etc/my.cnf. The most relevant ones in your case would probably be tmp_table_size and max_heap_table_size which, for MyISAM tables, should probably be identical. I use a value of 500M for each, which means large queries that cannot be satisfied by other caching methods can take up to 500 Mb before having to be written to disk.
> 
> If you have enough free RAM, you could set tmpdir to /dev/shm/, but this is a less efficient way of doing the same thing.

I would also suggest running mysqltuner.pl - it generally gives pretty good information on how your current settings can be changes to suit your load. You'll enjoy spending a few hours going through the manual working out how the settings interact and what they do - then tweak, restart MySQL and wait to build up fresh stats.

It does take some effort, but I can assure that a bit of tuning can really really improve your system. I forget the details now, but IIRC my system used to be quite sluggish (especially when rescheduling after after recording rule change), but after tuning would reschedule in a fraction of the time and normally before MythWeb redrew the upcoming recordings page.