[mythtv-users] SchedulesDirect timing out during Mythfilldatabase
mythtv at davidmcmillan.com
Sat Jul 23 21:58:41 UTC 2011
On Mon, Apr 18, 2011 at 11:02 AM, Rob Smith <kormoc at mythtv.org> wrote:
> On Mon, Apr 18, 2011 at 6:29 AM, Mark Lord <mythtv at rtr.ca> wrote:
> > But in the end, it just might be mysql doing an excessive number of
> > or "fdatasync()" calls. Databases like to do things that way, but it
> > mean they run very slowly when updating stuff
> I wouldn't call myisam's usage of fsync excessive... I'd call it
> majorly lacking.
> mythtv-users mailing list
> mythtv-users at mythtv.org
I've been researching this problem and appear to have gotten better
performance by adding the barrier=0 option to the line in /etc/fstab that
mounts the ext4 volume containing the mythconverg database. My
understanding is that you need to ensure that you don't have power blips
(use a UPS) when disabling write barriers. I'm also using LVM.
My per/schedule day process times in mythfilldatabase dropped from 10+
minutes to 2 minutes. With the --dd-grab-all option, total time was 17.5
minutes. Before the change it was 1-2 hours if it didn't timeout. IO wait
times have gone from 20% to 5.5% when running "iostat 5". My database type
-------------- next part --------------
An HTML attachment was scrubbed...
More information about the mythtv-users