[ale] Software RAID Problems

Danny Cox danscox at mindspring.com
Mon Mar 1 07:26:19 EST 2004


Hi, Jason!

On Sun, 2004-02-29 at 20:54, Jason Vinson wrote:
> I looked in the BIOS and I don't see a setting for toggling DMA.
> 
> But here's what I see from dmesg:
> 
> (this is my onboard ide controller)
> ide0: BM-DMA at 0xfc00-0xfc07, BIOS settings: hda:DMA, hdb:DMA
> ide1: BM-DMA at 0xfc08-0xfc0f, BIOS settings: hdc:DMA, hdd:DMA
> 
> (and these are the Promise IDE channels)
> ide2: BM-DMA at 0xdf50-0xdf57, BIOS settings: hde:pio, hdf:pio
> ide3: BM-DMA at 0xdf58-0xdf5f, BIOS settings: hdg:pio, hdh:pio
> 
> hde and hdg are my potential RAID devices, and they are set to pio.  So 
> is pio conflicting with DMA somehow, or should this not be affected by 
> DMA at all? And isn't there a way to turn off DMA via hdparm, or will 
> that not work here?

	That's just the kernel reporting how the BIOS was set up.  There are
probably messages just after that which show what else the driver set
up.  Use "hdparm /dev/hde" and see if DMA is 0 or 1.  If necessary,
sometime during bootup, add "hdparm -d1 /dev/hd{e,g}" to force DMA on.

	But your previous post showed the drives complaining about errors.  On
second glance, I see that 'dma_intr' is being called, confirming that
DMA is being used on hde at least.  The UncorrectableError is the main
culprit here.  Try running badblocks on the whole drive (smoke 'em if ya
got 'em, it'll take a wee bit ;-), and see what it says.

	HTH!

-- 
kernel, n.: A part of an operating system that preserves the
medieval traditions of sorcery and black art.

Danny



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