Debian (Knoppix) on HP a350n

[sms@sonic.net]

Quoth Rick...

> Let's review the Linux/SATA topic for a minute.

:-)

Always glad to add to my knowlege-base (SNIP'ing Rick for the sake of
BW)...

[ SNIP the advent of "SATA" & re-labelling of earlier as "PATA" ]
[ SNIP 2.4.x kernel support for these "modest exensions" to existing
  ATA chipsets; BUT (emphasis added) "some entirely new driver code...
  plus some revisions [to] existing drivers" is needed for reliability. ]
[ SNIP libata (J.Garzik)'s contribution to the 2.5.x/2.6.x kernels, &
  its rarity as a backport in 2.4.x kernels/installers. ]
[ SNIP the "limited... prone to freeze-up" state of non-libata kernel's
  & that successful install depends on the particular chipset & mode. ]

> If memory serves, your HP Pavilion A350N sports an Intel ICH5 SATA
> chipset.

Yes.

> The reason your hot-off-the-press Knoppix had no problem with
> that is twofold:
>
> 1.  The ICH5 is sufficiently similar to the earlier ICH4 and prior PATA
> chipsets (and thus the longtime ATA driver's piix support) that it
> doesn't (usually) have serious problems.

That isn't the... "impression" I got from the Google'ing & reading I did
last month.  I can only be happy it worked easier than I expected.

> 2.  Happily, one of the advantages of using hot-off-the-press Knoppix is
> that it gets you easy access to a very recent 2.4.x kernel.  Very recent
> 2.4.x kernels include tweaks to the piix support that cure freeze-ups
> encountered on ICH5 when using earlier 2.4.x kernels.  If you'd been
> using, say, an installer running 2.4.18, the installer might well have
> frozen up.

Yes; I *think* I'm running 2.4.24 (per the Knoppix site; but I'm away from
home & can't actually verify it); interestingly, it appears that libata
was added to 2.4.22 then "retired" in favor of 2.6 kernels (?), though I
may be mis-interpreting what I'm seeing.

[ SNIP troubleshooting installs, & tweaking the BIOS to "legacy PATA" ]

> Last, you re-enable SATA mode in the BIOS.  So, to revisit
> your statement:
>
> > Another bit of evidence is that we never diddled with the BIOS (as
> > prior SATA-on-Linux doc's implied was required).
>
> Um, no.  Not exactly _required_.  Simply often helpful.

I had understood that the options were 3:  (1) tweak BIOS; (2) use a
custom installer; (3) get a PATA drive.  I see (in Rick's page
http://www.linuxmafia.com/faq/Hardware/sata.html) that 2.4.21 & later
(and Knoppix, among other Distro's) seem to have "better" SATA-like
support... I hadn't noted that before (partly because I'd been looking
at earlier kernels)).

This was an oversight/misunderstanding on my part.   :(


>> My "helper" at the Installfest did a "hdparm -t" for some testing, and
>> suggests that the speed "looks like" it's running fully as a SATA
>> disk.
>
> Now, _that's_ a bunch of rubbish.  SATA raises the theoretical maximum
> bus bandwidth of an ATA bus, but it does nothing at all to make an ATA
> drive actually pump out data faster.

???

Quoting "http://www.linuxmafia.com/faq/Hardware/sata.html" again --
   "... libata is highly desirable since it supports many additional
   chipsets, and gives a ~10M/s speed boost to others.) "

I can see that the hdparm test may not have been a definitive test, but
it _looks_ (to the casual eye) as if a speed-test might show faster
access on a SATA drive if SATA support is enabled.  <shrug>  I'm FAR
from the cutting edge of knowlege, sadly, and while I was suspicious
of the "hdparm" (as a reliable "metric"), it doesn't really seem as if
this was really "rubbish" (as an off-the-cuff test).


> Anyhow, if you want to find what communications mode your ATA chain(s)
> is (are) set to use, look in the BIOS Setup screens.

That says how the HW is set; is there no linux command-line way to check
what the kernel is doing?


> But, if you think SATA vs. PATA makes a speed difference, think again.
> It really doesn't.

Actually, I'm *willing* to have it run faster; but honestly, I don't need
insane speed.  What I really want is a nice stable system, & so I don't
like to run in a dodgy "PATA compatible" mode that may hang/freeze my
kernel at some indeterminate future point...  It's rather looking as if
I'm gonna want to compile me a libata-enabled kernel.   :-P


>> Unfortunately, I *was* time-crunched, so I didn't quite have time to
>> finish all the config issues.  In particular, I haven't checked if I'm
>> stuck on a "poxy winmodem".  :-/    "lspci" baby... lspci all the way,
>> with a visit to Linmodem!
>
> Only you can decide how much your time is worth.  Me, I'd try to set up
> dial-up.  Then, if that seemed to fail for mysterious reasons, I'd give
> it up as a probable winmodem, and go buy a real (external, serial-port)
> modem to use instead.

:-)

I was actually thinking I'd try the Nike Method (just do it) for this; a
foray into "man -k" seems to point me at "wvdial" (a new command to me),
though I'd be glad enough for a pointer to anything "easier".  But, while
"winmodems" are admittedly non-real, IMHO "external, serial-port" modems
are also a bit... well, non-real (reminiscent of the archaic hobbyist
phase of the industry (think "Wargames")).  YMMV.

I've got financial constraints, too.  I can't just keep dropping $50 here
and there on the project to make up for deficiencies in existing HW.  I
will put in at least SOME time trying to make existing HW work.

Thanks again for all your help!


- Steve S.