Re: Dell XPS gen 3 trouble
On Wed, 15 Dec 2004 11:01:51 +0100
Søren Boll Overgaard <boll+debian@fork.dk> wrote:
> Hi,
>
> On Tue, Dec 14, 2004 at 03:55:20PM -0600, Jacob S wrote:
> > >
> 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.
Ok, this simply sounds like disabling raid.
> > 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
>
> > 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.
Unfortunately I don't know of a way to be able to boot both 2.4 and 2.6
kernels. If one fails and you need to boot the other, I would recommend
a rescue disk to edit fstab.
> > 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
You might try "hdparm -i /dev/hda" to see what it thinks your hard drive
is capable of doing. man hdparm will help with how to change those
settings.
> > 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
hmm... Your reads from cache on the hard drive are really fast, though
the reads from disk obviously leave a bit to be desired. I would
recommend trying a 2.6 kernel, as I'm told it's SATA support is a lot
better. (I've not done a comparison myself, since I didn't want to have
to fuss with changing fstab.)
> > 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.
Ok, just so long as you know you're probably hurting cpu performance a
bit.
HTH,
Jacob
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