[Bulk] [CentOS] hda dma seek errors

[Rohan Walsh]

>>> can find no problem with either drive. I disable dma as a temporary
>>> solution, but I think it is not a drive fault in my case. Do back
>>>up :)
>>>
>> How did you go about disabling dma?

>You only want to do that as a last resort, it makes your disk IO very
>slow.

>You would change it using hdparm ... the option would be:

>hdparm -d0
>
>You can make it happen every reboot by editing the file:
>
>/etc/sysconfig/harddisks
>
>set:
>
>USE_DMA=0
>
>and remove the # in front of it.
>
>AGAIN ... only if absolutely necessary, because it greatly slows down
>disk
>I/O.

I used ide=nodma as a kernel option in grub
I don't generally do much at the moment that requires high I/O, though I
would like to fix this. I will try changing cables.

Without dma:
# hdparm -Tt /dev/hda

/dev/hda:
Timing cached reads:   700 MB in  2.01 seconds = 348.48 MB/sec
Timing buffered disk reads:   12 MB in  3.69 seconds =   3.25 MB/sec

With dma:
# hdparm -Tt /dev/hda

/dev/hda:
Timing cached reads:   688 MB in  2.01 seconds = 342.34 MB/sec
Timing buffered disk reads:   28 MB in  3.09 seconds =   9.05 MB/sec