PowerEdge 750 w/SATA RAID

Jeff Garzik jgarzik at redhat.com
Fri May 21 12:52:00 CDT 2004

On Fri, May 21, 2004 at 10:51:16AM +0200, Glenn Provoost wrote:
> Hi,
> --On donderdag 20 mei 2004 16:49 -0500 Matt Domsch <Matt_Domsch at dell.com> 
> wrote:
> >Sure, that would work as well.  The SATA controllers on the PE700 and
> >PE750 are in "combined mode", but the ata-piix driver in FC1 should
> >handle them alright.
> I can confirm that the SATA controller in the PE750 works with the ata-piix 
> driver, however I can't manage to get DMA enabled on it on any kernel later 
> than 2.4.18-bf2.4 (which is on the debian bf2.4 boot floppies). This 
> renders me with pitiful performance on the I/O to the disks: something like 
> 3MB/s  :-( Even when I use the 2.4.18-bf2.4 config to compile e.g. 2.4.24, 
> I can't get DMA working. I get:
> [root at mymachine linux]# hdparm -d 1 /dev/hdc
> /dev/hdc:
> setting using_dma to 1 (on)
> HDIO_SET_DMA failed: Operation not permitted
> using_dma    =  0 (off)

If you were using the drivers/scsi/ata_piix.c driver, then your
devices would appear as /dev/sda not /dev/hdc.


Though Debian's 2.4.18 boot kernel is far too old to really support your
hardware, without building a custom kernel.


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