Need Help Editing Grub

[Eric Shubert]

Mark,
I don't understand entirely the commands that kitepilot said to use either.

Your menu.lst file looks correct.

savedefault, along with the "default" setting listed earlier in 
menu.lst, controls which kernel is used as the default. savedefault 
means "use me to boot next time", so generally speaking, the computer 
boots whichever OS was running last. Providing the "default" setting 
corresponds to this behavior.

makeactive and chainloader commands are used with windows partitions. 
makeactive makes the partition active (whatever that means, but windows 
seems to require it), and chainloader, which effectively passes control 
over to the windows loader program, not unlike what happens when the 
bios passes control to grub. At least that's what I would guess.

If grub is not installed in the mbr of the 2nd drive, it needs to be. I 
think that might be what kp was trying to get to. In order to install 
grub on mbr of drive hda, issue the "grub" command at the cli. Then at 
the grub prompt, enter the part after the prompt:
grub> root (hd0,0)
grub> setup (hd0)
grub> quit

If your OS is the 2nd partition on the drive, then you'd specify:
grub> root (hd0,1)

If your drive is hdb, then you'd use hd1 in place of hd0.

That drive would then run grub when it's booted.

-- 
-Eric 'shubes'


Mark Phillips wrote:
> This is what I have in menu.lst
>  
> title           Debian GNU/Linux, kernel 2.6.26-2-686
> root            (hd1,4)
> kernel          /boot/vmlinuz-2.6.26-2-686 root=/dev/hdb5 ro
> initrd          /boot/initrd.img-2.6.26-2-686
> 
> title           Microsoft Windows XP Professional
> root            (hd0,0)
> savedefault
> makeactive
> chainloader     +1
> 
> So, I change
> title           Debian GNU/Linux, kernel 2.6.26-2-686
> root            (hd1,4)
> kernel          /boot/vmlinuz-2.6.26-2-686 root=/dev/hdb5 ro
> initrd          /boot/initrd.img-2.6.26-2-686
> 
> to
> 
> title           Debian GNU/Linux, kernel 2.6.26-2-686
> root            (hd0,4) <-- change1 to 0 here
> kernel          /boot/vmlinuz-2.6.26-2-686 root=/dev/hda5 ro <--- change 
> b to a here
> initrd          /boot/initrd.img-2.6.26-2-686
> 
> and remove
> title           Microsoft Windows XP Professional
> root            (hd0,0)
> 
> What about these bad boys.....
> savedefault
> makeactive
> chainloader     +1
> 
> I still don't understand the grub commands that I was told to use.
>  
> Mark
> 
> On Sun, Jan 24, 2010 at 5:58 PM, Eric Shubert <ejs at shubes.net 
> <mailto:ejs at shubes.net>> wrote:
> 
>     "every reference to hd1,0 is converted to hd0,0"
>     You need to edit this manually. hd1 in grub corresponds to hdb in linux,
>     and hd0 in grub is hda in linux.
> 
>     Mark Phillips wrote:
>      > I understand the flow....shouldn't I tell grub somehow that the
>     new boot
>      > drive is hd0,0? In your steps below, is there perhaps, a typo?
>      >
>      > Thanks!
>      >
>      > Mark
>      >
>      > On Sun, Jan 24, 2010 at 3:58 PM, kitepilot at kitepilot.com
>     <mailto:kitepilot at kitepilot.com>
>      > <mailto:kitepilot at kitepilot.com <mailto:kitepilot at kitepilot.com>>
>     <kitepilot at kitepilot.com <mailto:kitepilot at kitepilot.com>
>      > <mailto:kitepilot at kitepilot.com
>     <mailto:kitepilot at kitepilot.com>>> wrote:
>      >
>      >      >> 1. How do I change grub on the Linux drive (hdb) to say
>     "the ...
>      >     If you are running GRUB 0.XX (GRUB 1.XX is different):
>      >     Boot your Debian machine and as root run:
>      >     grub
>      >     root (hd1,0)
>      >     root (hd1)
>      >     It should answer that it found the stages, verify that there
>     are no
>      >     errors.
>      >     quit
>      >
>      >
>      >     Then take a backup of /boot/grub/menu.lst and and make sure that
>      >     everything
>      >     is either using UUID(s) or labels or every reference to hd1,0 is
>      >     converted
>      >     to hd0,0
>      >
>      >     Verify your /etc/fstab likewise.
>      >
>      >
>      >      > 2. Do I move the second drive to the first ide port, or
>     leave it
>      >     as ...
>      >     Shutdown, pull the cable from the windoze drive and plug it
>     to Linux
>      >     drive.
>      >     Turn on and pray...   :)
>      >     Free advice, you can't sue me   ;-)
>      >     YMMV
>      >     ET
>      >
>      >
>      >
>      >
>      >     Mark Phillips writes:
>      >
>      >      > I have two ide drives in one machine - drive 1 is a
>     Windows drive
>      >     and drive
>      >      > 2 is a Linux drive. Using grub, I can boot into either
>     windows or
>      >     debian. I
>      >      > want to remove the windows drive and replace it with a larger,
>      >     blank drive
>      >      > for backup storage. I have a feeling if I just remove the
>     first
>      >     drive and
>      >      > put the new one there, the machine will not boot, since
>     the MBR
>      >     is probably
>      >      > on the first drive (it came with the machine, and I just added
>      >     the second
>      >      > drive for Linux). My questions:
>      >      >
>      >      > 1. How do I change grub on the Linux drive (hdb) to say "the
>      >     windows drive
>      >      > is dead, boot here instead, long live linux"?
>      >      >
>      >      > 2. Do I move the second drive to the first ide port, or
>     leave it
>      >     as the
>      >      > second ide drive and put the new drive in the fist ide port?
>      >      >
>      >      > Thanks!
>      >      >
>      >      > Mark
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-- 
-Eric 'shubes'