Getting dos hard drive to boot from lilo

Getting dos hard drive to boot from lilo

[Cheryl Homiak]

My new hard drive is up and working with linux; I was able to do it
without a reinstall. Really pretty easy once you figure it out the first
time.
We have now moved my dos hard drive to hdb (it was hdd before). I was
hoping not to have to boot in from floppy any more, but to use lilo as I
did when I had a windows os on hdb. I can boot in with a floppy, and I can
mount hdb1 and it is my dos hard drive. Both linux cfdisk and dos fdisk
show it as bootable. I've also used map-drive to switch the drives, but it
still won't boot. Not a huge problem, as I can go on booting from floppy
to dos as before, but I would like to know why this won't work. The
relevant part of my lilo.conf is included below.
Thanks.

Cheryl

other=/dev/hdb1
table=/dev/hdb
label=dos
#	restricted
alias=3
map-drive = 0x80
  to = 0x81
map-drive = 0x81
  to = 0x80

Re: Getting dos hard drive to boot from lilo

[L. C. Robinson]

On Thu, 6 Dec 2001, Cheryl Homiak wrote:

> We have now moved my dos hard drive to hdb (it was hdd before).
> I was hoping not to have to boot in from floppy any more, but
> to use lilo as I did when I had a windows os on hdb. I can boot
> in with a floppy, and I can mount hdb1 and it is my dos hard
> drive. Both linux cfdisk and dos fdisk show it as bootable.

It's unclear where lilo is installed.  The boot flag should be on
the partition where you have installed lilo (boot=/dev/hd??),
unless you have put lilo on the MBR (the Master Boot Record --
probably on /dev/hda, except newer BIOSes can be configured to
point elsewhere), in which case the boot flag is irrelevant.  If
you have had lilo on /dev/hda at any time in the past, you cannot
change to, say, the root or /boot partition (which is usually
where one would expect it, _not_ on drive hdb), until you first
restore the original dos style MBR.  The original MBR can then
honor your boot flag, so that your lilo install on another
partition can work. 

If this seems to be the source of the problem, the easiest way
out is probably to just go with lilo on the MBR, by making sure
you have in the global options:

boot = /dev/hda

and rerun lilo.

Alternatively, you can put the MBR back, by running the MS-DOS
fdisk with the /mbr switch (be very careful):

fdisk /mbr

Lilo also tries to backup the MBR, and there is a lilo option to
restore it, if the original backup file is still there.

If the above doesn't help, you may need to run lilo very
verbosely in the test mode and carefully inspect the output:

lilo -t -v -v -v > lilo.test.output
less lilo.test.output

Three -v options is probably about all you can stand, or would need,
and two might be enough, and a lot less messy.  Lilo won't
actually change anything in test (-t) mode, so you can make as
many tests as you want, till you're satisfied, then remove the
-t and extra -v options to actually write the disk.

> I've also used map-drive to switch the drives, but it still
> won't boot. Not a huge problem, as I can go on booting from
> floppy to dos as before, but I would like to know why this
> won't work. The relevant part of my lilo.conf is included
> below.

I checked the manual, and can't spot any errors in this next
part:

> other=/dev/hdb1
> table=/dev/hdb
> label=dos
> #	restricted
> alias=3
> map-drive = 0x80
>   to = 0x81
> map-drive = 0x81
>   to = 0x80

Hope this helps, LCR

-- 
L. C. Robinson
reply to no_spam+munged_lcr@onewest.net.invalid

People buy MicroShaft for compatibility, but get incompatibility and
instability instead.  This is award winning "innovation".  Find
out how MS holds your data hostage with "The *Lens*"; see
"CyberSnare" at http://www.netaction.org/msoft/cybersnare.html

Re: Getting dos hard drive to boot from lilo

[Gil Andre]

Cheryl,

I am not 100% sure I understand your problem, so what I write
below may be completely wrong... As far as I understand it,
you are trying to boot DOS (or Windows) from /dev/hdb_, with
Linux probably installed on /dev/hda_

This is a limitation of DOS/Windows systems: they can only be
booted from the first hard disk of your machine (/dev/hda_).
These operating systems simply assume they are the first, only
and/or most important operating systems on your hard disk and
will simply refuse to boot from any other drive.

Whether this behavior is a bug or a feature of Windows systems
is left as an exercise to the reader... <grin>

I think the only way out of your problem would be to install
your Windows hard disk as the first disk in your machine and
move the Linux hard disk in another position, since Linux
does not have the limitations of Windows. A very good source
of information for this is the Lilo mini-howto, that you'll
find at the following address:
http://www.linuxdoc.org/HOWTO/mini/Multiboot-with-LILO.html

Another good source of information is the hard disk upgrade
"howto":
http://www.linuxdoc.org/HOWTO/mini/Hard-Disk-Upgrade/

And a final source of info would be the Multiple OS howto:
http://www.linuxdoc.org/HOWTO/MultiOS-HOWTO.html

Hope this helps!

_______________________________________________

Gil Andre -- Technical Writer -- Knox Software
            gandre@arkeia.com
_______________________________________________

On Thu, 6 Dec 2001 06:51:11 -0600 (CST)
Cheryl Homiak <chomiak@chartermi.net> wrote:

> We have now moved my dos hard drive to hdb (it was hdd before). I was
> hoping not to have to boot in from floppy any more, but to use lilo as I
> did when I had a windows os on hdb. I can boot in with a floppy, and I can
> mount hdb1 and it is my dos hard drive. Both linux cfdisk and dos fdisk
> show it as bootable. I've also used map-drive to switch the drives, but it
> still won't boot. Not a huge problem, as I can go on booting from floppy
> to dos as before, but I would like to know why this won't work. The
> relevant part of my lilo.conf is included below.
> Thanks.

Re: Getting dos hard drive to boot from lilo

[L. C. Robinson]

On Fri, 7 Dec 2001, Gil Andre wrote:

> ...
> This is a limitation of DOS/Windows systems: they can only be
> booted from the first hard disk of your machine (/dev/hda_).

But you will observe that she used some lilo trickery to make
MS-DOS think it was booting from the first drive, by logically
swapping the drives.  I have used this scheme successfully for
years, on my own machine (till the drive went flaky -- haven't
even missed it -- got to where I hated the frustrations that toy
OS put me through, and almost never booted it anyway).

> These operating systems simply assume they are the first, only
> and/or most important operating systems on your hard disk and
> will simply refuse to boot from any other drive.

Annoying, isn't it.  But she will be able to fool the stupid M$
stuff, when she gets the rest of her config right.

> ...
> I think the only way out of your problem would be to install
> move the Linux hard disk in another position, since Linux
> ...

But, you see, she already knows about another way out.

<rest snipped>

-- 
L. C. Robinson
reply to no_spam+munged_lcr@onewest.net.invalid

People buy MicroShaft for compatibility, but get incompatibility and
instability instead.  This is award winning "innovation".  Find
out how MS holds your data hostage with "The *Lens*"; see
"CyberSnare" at http://www.netaction.org/msoft/cybersnare.html

Re: Getting dos hard drive to boot from lilo

[Gil Andre]

I stand corrected!   <grin>

On Fri, 7 Dec 2001 02:10:42 -0700 (MST)
"L. C. Robinson" <lcr@onewest.net> wrote:

> On Fri, 7 Dec 2001, Gil Andre wrote:
> 
> > ...
> > This is a limitation of DOS/Windows systems: they can only be
> > booted from the first hard disk of your machine (/dev/hda_).
> 
> But you will observe that she used some lilo trickery to make
> MS-DOS think it was booting from the first drive, by logically
> swapping the drives.  I have used this scheme successfully for
> years, on my own machine (till the drive went flaky -- haven't
> even missed it -- got to where I hated the frustrations that toy
> OS put me through, and almost never booted it anyway).


_______________________________________________

Gil Andre -- Technical Writer -- Knox Software
            gandre@arkeia.com
_______________________________________________