[mythtv-users] Hard Drive Performance

[Tom Lichti]

Ryan Steffes wrote:
>
>
>     Your buffered reads look more or less normal, but your cached reads
>     are less than half of what they should be. I get over 1900 MB/sec.
>     for cached reads.
>
>     Are you sure DMA is enabled for your drives ?? Was the system doing
>     anything else when you ran the tests?
>
>     You never want to put a hard drive on the same IDE bus as an optical
>     drive, it will slow the HDD down to the (probably 33) speed of the
>     latter. You should put both of your hard drives on the primary IDE
>     channel. This, however, does not explain the slow speed of your /dev/
>     hda drive, but it would explain problems with /dev/hdc.
>
>     Make sure you are using a proper 80-conductor cable for your hard
>     drives as well, you need to be running in UDMA mode to get top
>     performance (assuming your Motherboard has a modern IDE interface,
>     without that you're pretty much dead in the water).
>
>
> The system was recording during that test, I can shut myth down later 
> to get "clean" numbers if it would help.  DMA is on for both drives.
What does hdparm -d /dev/hd? show?

Tom