On Wed, 2003-05-14 at 10:50, Olaf Frączyk wrote:
> On Wed, 2003-05-14 at 17:21, Walt H wrote:
> > Do you have dma enabled on your IDE disks? I can't think of any reason
> > off the top of my head why a cat from hda -> hdc should be affected by
> > XFS, as you aren't using the filesystem for that - it's just reading the
> > raw device.
> Yes, I know. I just don't know if XFS code changes some buffering etc.
> Maybe with vanilla kernel it would be the same. I just have no easy way
> to test it.
> Make sure dma is enabled on hda and hdc and see if that
> > helps: hdparm -d1 /dev/hda /dev/hdc
> Both drives have dma enabled.
> And they are set to UDMA-100 also.
> I'm just curious where from comes this terrible latency.
XFS should not affect this in any way, I am sure the unmodified kernel
would behave the same way for you.
Steve Lord voice: +1-651-683-3511
Principal Engineer, Filesystem Software email: lord@xxxxxxx