[mythtv-users] High mysql cpu usage

[Terjesen Jens Peder]

-----Original Message-----
On: 30. desember 2012 8:28 Michael T. Dean wrote

On 12/30/2012 12:25 PM, Jarle Thorsen wrote:
> 2012/12/30 David Scammell
>
>> At the end of the day I'm unsure if there's a problem with indexes 
>> but my situation was fixed by setting the visible=0 setting on a 
>> number of 'useless' channels that i'm unlikely to record from, 
>> bringing the number of visible channels to about 90. My longest slow 
>> query is now
>> 13 seconds, once or twice a day.
>>
> I have currently about 700 channels, and I am in the process of 
> deleting channels that I can not tune in to. I'm thinking that my 
> number of
> (possibly) bad channels may contribute to my problem.
>
> I have seen some reports of similar problems for ext4 users, but I'm 
> not running ext4 on my box.

It's not just ext4.  It's most any file system with barriers enabled--because that slows write speeds to platter write speeds (it completely disables disk cache (in software /and/ hardware) for writes).

Mike


-----Original Message-----

I have this very same problem.

After I got my UPS working satisfactory on my combined BE/FE I have disabled barriers on the ext4 partition for the OS and DB. This has not made any change.

Jens