Re: Getting dos hard drive to boot from lilo

["L. C. Robinson" <lcr@onewest.net>]

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

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