[mythtv-users] Commflag-related IOBOUND errors

R. G. Newbury newbury at mandamus.org
Thu Jan 19 19:30:41 UTC 2006


Brandon Beattie wrote:

>This is purely a system and disk IO issue.  I have my mysql databases on
>a seperate drive than recordings, but I still get IO bound issues once
>in a while.  The thread for rescheduling does take all the CPU and IO it
>can get for those few seconds, and with the mysql and disk writing
>threads they don't always work well together.  It's a known problem but
>only shows up for HD users more so because HD requires such a large
>amount of bandwidth and it can't really stand a hickup.  Also, the PCI
>bus can be occupied and cause data from the card to be lost if the
>system IO can't be freed up quick enough to handle the data.  HD tuner
>cards have a rather small cache on them.  If anything occupies the
>system IO longer than 500ms then you risk losing data from the HD tuner,
>and Myth and the scheduler does this at times.
>  
>
This seems to imply that the mysql database might best be placed on a 
separate SCSI drive with a large cache? Any thoughts?

Geoff


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