[PLUG] IO issues...

[Robert Anderson]

On 10/21/05, Robert Anderson <riznob at gmail.com> wrote:
>
>
>
> On 10/21/05, AthlonRob <athlonrob at axpr.net> wrote:
> >
> > Robert Anderson wrote:
> > > Hi everybody, I am having some issues with IO on my mythtv box (Fedora
> > 3,
> > > not the latest kernel). While watching certain programs skipping ahead
> > 30
> > > seconds can be quite slow, like 5 seconds, and jumping ahead 10
> > minutes may
> > > take 3-4 minutes. I have been watching top and using iostat to get
> > some more
> > > information about what the bottleneck might be. Top shows a high CPU
> > iowait
> > > percentage, around 70-80%, during the delay. Also iostat shows a lot
> > of wait
> > > also. I thought that perhaps defragmenting the partition would help,
> > but it
> > > has not really done much, yet. I have noticed some improvement, but
> > the
> > > problem has not gone away. The filesystem where the programs are
> > stored is
> > > XFS. Any help or suggestions are appreciated.
> >
> > Well, first question: is DMA enabled on that hard drive?
> >
> > Rob
> > _______________________________________________
> > PLUG mailing list
> > PLUG at lists.pdxlinux.org
> > http://lists.pdxlinux.org/mailman/listinfo/plug
> >
>
> How can I tell if it is?
>
> --
> Rob Anderson
> riznob at gmail.com
>

Yes. DMA is enabled.

$ hdparm /dev/hda

/dev/hda:
multcount = 16 (on)
IO_support = 0 (default 16-bit)
unmaskirq = 0 (off)
using_dma = 1 (on)
keepsettings = 0 (off)
readonly = 0 (off)
readahead = 256 (on)
geometry = 65535/16/63, sectors = 80026361856, start = 0


--
Rob Anderson
riznob at gmail.com