Re: Dual_Boot:_RH7.2&Win2K

On Sat Mar 15 2003 at 19:37, "dhd" wrote:

> Content-Type: text/html;
> 	charset="iso-8859-1"
> Content-Transfer-Encoding: quoted-printable

Please, no html to mailing lists.  please?

(You can control that in outlook, make it do text/plain for email to
specific places... make all your @redhat.com email like that).

> Hi,  I'm having difficulty configuring my boot process to work the
> way I'd like.

Right, and you want to do it all from the grub menu right at bootup,
without the need to use boot floppies and so on.

The exact details of your local hardware configuration aren't clear,
so modify what I say below for your situation.

> I'd like to have the option to boot form either Win2K or RH7.2 on
> start up.  The only way I've been able do to this so far requires
> booting RH from a floppy.

That's good if you have it working like that... keep those floppies
handy and maintian them... it can save you some grief when things go
astray.  Beware, you are dealing with windows and (depending on what
you are doing) it can, and does, overwrite your boot sector.

  But then, you always have rescue mode available to fix things,
  with the redhat installer disks.  It is relatively easy to use a
  rescue disk to get grub re-written to the boot sector.

Aside:
  If you have never seen knoppix, it is worth finding a copy:
	http://www.knopper.net/knoppix/index-en.html
  This is a full gui boot cdrom, that runs from a 1.8Gb filesystem
  based on a compressed loopback filesystem on the cdrom.  It makes
  a great rescue disk (*everything* is there), and by default it
  runs with kde as the window manager.  It has openoffice there and
  a full choice of apps.   All booted and running from a cdrom.  In
  a network with dhcpd running, it comes up all ready to talk to the
  network - even sound works :)

> I'm using GRUB and  have tried this two ways with the
> following results:
> --Putting the boot loader on the MBR I get the option screen to boot RH7.2
> or DOS;

For grub, that's not technically correct.  Lilo works more like
that, but grub is different.

  lilo requires that after you edit /etc/lilo.conf, you need to run
  /sbin/lilo to "stamp" the configuration changes into the boot
  sector (MBR), hard-coded, before they take effect.

When you run /sbin/grub-install, the grub bootloader gets put into
the MBR, and it works by reading a configuration file that it expect
to find in /grub/grub.conf (/boot is taken as grub's "root"... see
the docs for grub for exactly how this works, and below for an
example).

You'll notice that /etc/grub.conf is a symlink to
../boot/grub/grub.conf.

Whatever gets put into this file is seen and used by grub each
bootup.  There is no need to re-install grub into the boot sector
after the config file is changed -- changes are automatically used
at the next bootup.

Grub itself adds great a deal of flexability and boot-time control.
You can alter things on the fly with grub's boot-time editing and
command shell facilities.  For example, you can add completely new
bootup entries or heavily edit existing ones.  If you have a bad
entry that has a typo in the name of the kernel image, then you can
edit it to make it work.  You could also use grub's shell to verify
that a kernel or initrd image exists.  You can't do any of this with
lilo.

> however the DOS selection does not boot my Win2K install
> (I don't know why, could it be because it is NT/2000 on NTFS
> partition and not win95/98 on FAT?)

No, that wouldn't be the reason.  The bootloader just hands control
over to whatever is the boot image.  If that image is bad or not
found, then the boot fails.

Try it something like this in /etc/grub.conf

# bootable fat/ntfs partition in /dev/hdb1
title dos
	rootnoverify (hd1,0)
	# you might need to do this:
#	makeactive
	# don't use chainloader if on the primary boot disk
	chainloader +1
# linux installed on /dev/hda
# /boot = /dev/hda1 = (hd0,0)
# /     = /dev/hda5 (where /sbin/init lives for the kernel to find)
title linux
	root (hd0,0)
	kernel /vmlinux-2.4.18-26.7.x ro root=/dev/hda5 vga=775
	initrd /initrd-2.4.18-26.7.x.img

Also, for a two-disk plus floppy boot configuration, make sure that
you have something like this in /boot/grub/devices.map

(fd0)	/dev/fd0
(hd0)	/dev/hda
(hd1)	/dev/hdb

Re-run "/sbin/grub-install /dev/hda" whenever you need to change
_this_ file.

This schema is highly flexable... it is possible to have multiple
operating systems (eg, w98, w2k, rh7.3, rh8.0, debian 3.0, *BSD,
etc) installed onto any number of disks on your system, and (of
course with some careful planning) you are able to use grub to boot
into and happily use any one of them.

> --Putting the boot loader ont the first sector of the boot partition, Win2k
> starts up unless I use a boot floppy for RH.  Although this seems to work
> fine, I'd really like to take the opportunity to try and learn how to
> configure this correctly.  Any help would be greatly appreciated. THANKS!!!

Experiment with the above, and do some reading on grub.

I used to have some great bookmarks that pointed to some great tips
for using grub, but I seem to have lost them :(  However, there is
always http://www.grub.org/ and you could also do a search at
http://google.com/linux and see what that turns up for you.

I'm sure that you'll get this working seamlessly just as you want.

Have fun!

Cheers
Tony
---*#*=-=*#*=-=*#*=-=*#*=-=*#*=-=*#*=-
 Tony Nugent <Tony*linuxworks.com.au>
 LinuxWorks  Gold Coast Qld Australia
 Network and Systems Consultant, RHCE