Knoppix can see /dev/sda but BIOS cannot
 

I was running the Live Knoppix CD.

Before it booted up, it found a swap
partition sda2 (on a SCSI disk)
and started using it. That was good.

Then I did a hard disk install on the SCSI
disk. So:
/dev/sda1 has the root file system
/dev/sda2 has the swap file system
and a boot floppy was also created.

So when I reboot with the floppy, I get:
Grub error 21
The selected disk does not exist.

And the Grub Manual says:

21 : Selected disk does not exist
This error is returned if the device part
of a device or full file name refers to a
disk or BIOS device that is not present
or not recognized by the BIOS in the system.


This is true. The BIOS does not see my
SCSI hard disk but it is there and the Knoppix
Live CD does see it because it did the hard-disk
install on sda1 and it always uses the swap on sda2.

The SCSI hard disk is attached to the PCI SCSI
controller. The controller is seen by Knoppix
but not the BIOS.

So what do I do?
How can I get it to boot from /dev/sda1 ?

There are no other hard disks on the PC.
Only 1 CDROM drive on /dev/hda.

What kind of box are you using: laptop, desktop, other?

Which BIOS are you using: Award, Ami, other?

How old is your current BIOS? May be time to upgrade the BIOS.

Have you tried to edit the BIOS to get it to recognize the disk?

It is an old Desktop. Pentium 400Mhz.
Award BIOS.
At boot time, I can press the "Del" key to get in the BIOS.
Yes, I have tried to edit the settings but no luck.
The BIOS is just not aware of this SCSI disk.
The BIOS is only aware of the CDROM which is
directly connected to the IDE port on the motherboard.

Only thing that comes close is the boot order settings.
I changed those to "SCSI, C, A" and then "SCSI, A, C".
None of these worked.
It just hangs there after the memory test.

Well, if your BIOS has SCSI option then it can support add-on SCSI controllers. Probably the SCSI controller itself is not set up properly. Go to SCSI BIOS and see if you can enable it's booting features.

The SCSI card is a PCI Adaptec AHA-2910C.

So from the Adaptec web site I downloaded:
SCSISelect Utility v1.00

It correctly identifies my SCSI card and Hard Disk.
But how to I enable the booting feature(s)?
What should I (generally) look for?

At the moment, the SCSI ids are:
7 for SCSI card
1 for Hard disk

You can access (Adaptec) SCSI BIOS by depressing CTRL+A at boot time. Once in there you can set which disk to boot from plus many other settings. You should set your bootable HDD to ID 0:0 using jumpers, this is default in controller BIOS too. ID 7 for controller is OK, leave it that way. And remember, building a SCSI chain is not as simple as connecting IDE drives. You'll get rotten performance if anything is set up incorrectly. Good luck. :)

I don't see or get to do a CTRL+A at boot time.

But. it looks like the CTRL+A SCSI BIOS screen
is the same the SCSISelect Utility downloaded
from Adaptec.

The jumpers on the SCSI Hard Disk (WDE 4360)
are already set to ID 0.
But in the Adaptec SCSI BIOS the Hard Disk
shows up as ID 1.

There are no other SCSI devices in this PC.
The Adaptec card is set to auto terminate.

You need to depress CTRL+A at exactly right time, it may require some experimenting before you get it right.
If your drive shows up as ID 1 then ID 1 it is. Double-check the jumpers, you probably need to remove all 4 to get ID 0. Controller set to auto-terminate is good, what about the other end of cable? Tip: The jumper marked "TERM-PWR' does not enable internal terminator! (this is the most common mistake SCSI beginners do)

On other PCs, I have seen the Adaptec CTRL+A
at prompt boot time.

On this PC, I have never seen it at all.
Hard or soft boot. I have been booting
up this PC for a few months.

The Western Digital 4360 had jumpers on the pins marked:
TERM PWR (4th pair of pins, from the top)
SCSI TERM (6th pair of pins, from the top)
SCSI ID0 (17th pair of pins, from the top)

The 17th pair of pins is also the 1st pair
of pins from the bottom.

So the hard disk SCSI ID 0 is now consistent.

I took your advice and removed the jumper from
the 17th pair of pins. Then I powered on the PC.
Now the Adaptec SCSISelect utility says
that the Western Digital 4360 is ID 0.
(Previously, the utility said it was ID 1.)

Are the TERM PWR and SCSI TERM jumper settings ok?

Btw, the Adaptec SCSISelect utility says that
Plug and Play SCAM support is Disabled.
Is this ok? Or should I enable it?

The feature "Show CTRL+A at bootup" can be disabled - it still works indeed.

TERM PWR - This enables power for an external terminator, you won't need it if internal terminator is enabled (Not all disks have internal terminators)

SCSI TERM - must be enabled if this is the last unit on the SCSI chain

You do not need PnP SCAM.

Tip: Make sure the cable has no loose ends - i. e. one end is connected to controller and other end to the HDD with termination enabled.

I checked the SCSI cable.
It is snug. I swapped it with another flat SCSI cable.
It made no difference, same results.

Two more things to check in SCSI BIOS setup:
1. BIOS must be set to 'Enabled'
2. Device you boot from - ID 0 - must be included in BIOS scan.
I'm out of ideas now.

As per Adaptec documentation, turns out that the Adaptec AHA-2910C SCSI card is not bootable.

So I used the suggestions mentioned in this post:
http://www.knoppix.net/forum/viewtop...ht=loadlin+exe

Now I boot from a DOS floppy.
Instead of using the CDROM, I copied the contents of the
KNOPPIX CD on an 800 Mb FAT partition on the SCSI disk.

(I need the CDROM to be free for other uses.)

I used Adaptec's scsi drivers to boot from the floppy
and access the 800 Mb "C" drive.

Loadlin can boot linux.
In other words, loadlin.exe on the floppy (for DOS) boots Kooppix (on the SCSI hard disk).