Re: Dell XPS gen 3 trouble
Hi,
On Tue, Dec 14, 2004 at 03:55:20PM -0600, Jacob S wrote:
> >
> > 1) The Dell XPS comes with two 160 GB sata drives, which are only
> > usable from Linux when configured for pata access[1]. I have been
> > unable to enable DMA[2] on the disks, which is obviously detrimental
> > to performance. Any suggestions as to how to accomplish this would be
> > greatly appreciated.
>
> What makes you say they're configured for pata access? Did you have to
> change bios settings for d-i to see them? Are you using raid? (If so,
> almost all sata raid controllers built into motherboards are really a
> sneaky way of using software raid, which requires additional
> configuration in Debian.)
The machine comes stock with a raid controller. I had to disable the raid
functionality for d-i to actually see any drives. Doing so resulted in what the
dell refers to as "sata/pata combination mode". I have no idea if that is
common terminology. So, to answer your question, to the best of my knowledge no
raid functionality is currently enabled.
> The dmesg excerpt you mention below does not convince me it sees the
> drives as pata instead of sata, as all 2.4 kernels assign hd* devices to
> sata drives, in my understanding. I also didn't see what kernel version
> you are running (assuming it's not 2.6.9, since you mention boot
> problems with that version).
2.4.27-1-386, the one installed by d-i.
The entire dmesg output is at http://e.wheel.dk/~boll/stuff/dmesg.gz
>
> > 2) I am unable to boot the latest 2.6 kernel[3] as distributed in
> > debian unstable. The boot proceeds nicely, until detecting the second
> > disk, after which it just sits there. No kernel panic, nothing, it
> > just sits there. The keyboard is still active (ie. anything typed
> > appears on screen) but nothing happens.
>
> I've had the best success with a 2.6.7 kernel from Debian packages.
> 2.6.8 didn't fully load the modules I needed (ps/2 mouse) and I've not
> tried 2.6.9 (running Sarge).
>
> Also, if you really are using a 2.4 kernel during installation and then
> trying to boot the 2.6.9 kernel from unstable, that is probably the
> cause of your problem. 2.6 kernels label sata drives with a /dev/sd*
> device and 2.4 kernels use /dev/hd*. This will cause a sudden stop when
> it reads your /etc/fstab file and only sees references to /dev/hda
> which now looks like a non-existent device.
That would probably explain it. However, I am not certain how to change fstab
in a way that will allow me to boot a 2.4 kernel, in case booting a 2.6 series
kernel fails.
I will fiddle with it though, to see if I can get it to work.
> What does "hdparm /dev/hda" report?
# hdparm /dev/hda
/dev/hda:
multcount = 16 (on)
IO_support = 0 (default 16-bit)
unmaskirq = 0 (off)
using_dma = 0 (off)
keepsettings = 0 (off)
readonly = 0 (off)
readahead = 8 (on)
geometry = 19457/255/63, sectors = 160041885696, start = 0
> Using 2.6.7 kernel, it doesn't even
> tell me if udma is on or off and errors out similar to yours when I tell
> it to enable it. Nevertheless, hdparm -t /dev/sda and hdparm -T /dev/sda
> report pretty good speeds for me:
>
> # hdparm -t /dev/sda
>
> /dev/sda:
> Timing buffered disk reads: 158 MB in 3.08 seconds = 51.29 MB/sec
>
> # hdparm -T /dev/sda
>
> /dev/sda:
> Timing cached reads: 1024 MB in 2.00 seconds = 511.31 MB/sec
# hdparm -T /dev/hda
/dev/hda:
Timing cached reads: 4420 MB in 2.00 seconds = 2210.00 MB/sec
# hdparm -t /dev/hda
/dev/hda:
Timing buffered disk reads: 12 MB in 3.28 seconds = 3.66 MB/sec
> It won't make the difference between booting or not booting, but you'll
> probably get better performance from a kernel ending in one of the
> following instead of -386:
Yeah I know, I just went with the 386 one to reduce the number of things that
could potentially go wrong, ie. 686 specific instructions.
Your help is greatly appreciated.
--
Søren O. ,''`.
: :' :
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