IDE DMA problem [WAS: Re: Getting lousy NFS + tar-pipe throughputon 2.4.20]

From: Timothy Miller
Date: Fri Feb 13 2004 - 19:10:53 EST



I have discovered one major problem that I didn't think to check before. I have never before had trouble using DMA with WD drives, VIA chipsets, or RH9, so I didn't think to check before, but hdparm reports that DMA is disabled for the disk on the workstation I mentioned in my earlier post.

So, I tried this:
hdparm -d1 /dev/hda

And I got this result:
/dev/hda:
Setting using_dma to 1 (on)
HDIO_SET_DMA failed: Operation not permitted
using_dma = 0 (off)

How do I fix this? Do I have to unmount the filesystem before I can change the dma setting? Why would it be off to begin with? I know that the BIOS is set up right. Does 2.4.20 not work well with the KT600 chipset?

Thanks.


Timothy Miller wrote:
> [snip everything about slow NFS performance]



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