tlug: Debian installation - scsi problem

["Stephen J. Turnbull" <turnbull@example.com>]

>>>>> "Ulrike" == Ulrike Schmidt <ulrike@example.com> writes:

    Ulrike> I am currently at work trying to install (for the first
    Ulrike> time) Debian 2.1 on a

Ooops, I should have keyed on "first-time Debian."  I probably have
the same thing installed on my notebook.  Lessee ... hmm, no saved
.config.  OK, I do have a saved /boot/config-2.2.10 with the following
settings:

CONFIG_SCSI=y				# SCSI is BUILT-IN
CONFIG_BLK_DEV_SD=y			# SCSI disk is BUILT-IN
CONFIG_CHR_DEV_ST=m
CONFIG_BLK_DEV_SR=y			# SCSI CD-ROM is BUILT-IN
# CONFIG_BLK_DEV_SR_VENDOR is not set
CONFIG_CHR_DEV_SG=m
CONFIG_SCSI_AIC7XXX=y			# Adaptec AIC7xxx support is BUILT-IN
# CONFIG_AIC7XXX_TCQ_ON_BY_DEFAULT is not set
CONFIG_AIC7XXX_CMDS_PER_DEVICE=8
CONFIG_AIC7XXX_PROC_STATS=y
CONFIG_AIC7XXX_RESET_DELAY=15

I see no reason why this policy of compiling those features into the
boot install kernel would have changed, so all of the things that are
happening for you seem perfectly normal, except for the failure to
automatically detect the SCSI CD-ROM.

In /lib/modules/2.2.14/scsi you will have st.o, sg.o, and a couple of
others I don't recognize.  You should _not_ have scsi_mod.o or
sr_mod.o (because they're built in) so the "can't find" messages are
perfectly normal (you've guessed that by now, but let's make it
perfectly clear ;).

    Ulrike> Fujitsu FMV-590DE which seems to have a scsi CDROM,
    Ulrike> Adaptec, AHA-2940. I

OK, so you should be OK.

As Selva suggested, "dmesg | grep '^scsi : [0-9]* host'" wil show
whether any hosts were detected, "dmesg | grep 'scsi0'" should tell
you about the first SCSI host (if any), and "dmesg | grep 'Detected.*scsi'"
will show you the devices which were detected.  (I won't guarantee any
of those but they work on my boxes with an AIC7xxx but no SCSI CD-ROM
and a Buslogic with SCSI CD-ROM respectively.)

`dmesg' is the standard way to remember the kernel messages.
(Unfortunately, not _everything_ anybody would want _ever_ to know is
there, but in this case if it's not in dmesg, it didn't happen.)

Everything below is moderately educated guesswork, I am not a
qualified hardware jock.  But since the hardware jocks have not seen
fit to step in to the discussion, I'll take a shot at it.

    Ulrike> know what the proper settings are. The Adaptec menu for
    Ulrike> "Host Adapter SCSI Termination" gives three options:
    Ulrike> automatic, enabled, disabled. Which is the correct
    Ulrike> setting?

"Automatic" should work.  If you have _both_ external and internal SCSI
devices hooked up, you could try "disabled".  If you have only
internal, or only external, devices hooked up, you could try enabled.

    Ulrike> /proc/scsi/scsi says: "Attached devices: none" Interesting

OK, your CD-ROM is NOT being recognized.  This could be due to faulty
termination.  Or it might just not be hooked up.  If it is internal,
open the case and make sure the SCSI cable is firmly seated on both
the adaptor and the CD-ROM drive, and that the power cable is firmly
attached to the CD-ROM drive.  Does the CD-ROM drive have a power
light (they usually do)?  Does it come on?  If it's external, before
opening any cases, check that the external housing is plugged in, the
SCSI cable is properly plugged in to both the SCSI adaptor and the
external case, and that the power switch on the external case is on.
(Yeah, you've probably done this already but let's be thorough.  If
Austin has to make a house call for an unplugged power cord we'll
_never_ hear the end of it!)

If all cables are OK and the power is on, it could be termination.  If
the CD-ROM is the ONLY device hooked to the SCSI adaptor, then both
the adaptor (set "enabled" in the BIOS") and the CD-ROM (sorry, dunno
'bout this one but it's probably a jumper, you'll have to read the
docs or call in the vendor if they didn't supply docs) should have
termination.

If there are OTHER devices on the SCSI bus (hard drives, scanners,
tapes, whatever) then we need to know in what order they appear on the
internal bus (if any) and the external bus (if any).  The rule is that
the SCSI host should be at one end of each bus (physically, an
internal cable with several sockets or a daisy-chain of external
devices).  If both buses have devices on them the host must not be
terminated, otherwise the host must be terminated.  The device which
is farthest (counting along the cable or daisy-chain) away from the
host on each bus should be terminated, none of the others should be
terminated.

    Ulrike> for me who does not understand a thing is that there is
    Ulrike> also a file /proc/scsi/aic7xxx ... ???

The 2940 is a "SCSI host", the CD-ROM drive is an "attached SCSI
device".  The fact that you have /proc/scsi/aic7xxx means there's an
excellent chance that the SCSI board is working fine.

-- 
University of Tsukuba                Tennodai 1-1-1 Tsukuba 305-8573 JAPAN
Institute of Policy and Planning Sciences       Tel/fax: +81 (298) 53-5091
_________________  _________________  _________________  _________________
What are those straight lines for?  "XEmacs rules."
--------------------------------------------------------------------
Next Nomikai Meeting: April 20 (Thu) Linux Conference 2000 Spring Ed.
Next Technical Meeting: May 13 (Sat) 13:30 Temple University Japan
* Topic: TBD
--------------------------------------------------------------------
more info: http://www.tlug.gr.jp        Sponsor: Global Online Japan