Howto: change boot loader
 

When I originaly set up RH I set it up to boot from a floppy (I didn't want it to alter the MBR) with Windows as the default.
Now I changed my mind and I want RH's boot loader to take over but still have the option to go into Windows. How is this done? Through the installation disc?
Thanks.

Boot off the CD's select the upgrade option. Once it checks out that you have nothing to upgrade select install the bootloader(GRUB). W2K should be written on the MBR so GRUB should detect it automatically.

Great. Will try. Thanks.

Well, I tried it.
It does detect Windows XP on the MBR (although it lists it as DOS...), but then when setup finishes it says that no updates to the boot loader were made and indeed nothing changes.
I tried the Update option and I tried the Create New Configuration option but both do nothing. It's like the setup thinks that GRUB is already on the MBR and decides not to do anything else when in fact it's not...
Should I consider using another bootloader or did I miss something?

BTW, I found this help page which warns not to install GRUB on the MBR if running XP.
http://www.geocities.com/epark/linux...w2k-HOWTO.html
Now I'm totally confused.

Did you create a /boot partition before the first 1024 cylinders? that is vital otherwise your hardware won't be able to install GRUB or if it does get it to work. Presumably you haven't if XP was on your system before. You'll either have to reinstall both OSes or keep booting off the floppy.

wow, that's a shame. Are you positive that no amount of partition magic can fix this situation?

Come to think of it, the size of the HD that has linux is only 3GB! So it can't really be a 1024 cylinder problem, can it?

How many hard disks have you got in there? If you have two then you can just change the jumper so the Linux disk is the bus master and the other to cable select or slave then you just install the boot loader, I *think* then GRUB can boot off the second HD but don't quote me on that

Actually I'm worried about that configuration. It seems that windows NTLDR only wants to sit on the MBR and doesn't work from a secondary partition.
Is it possible you think to somehow _move_ the NTLDR to the other HD after switching and making it primary?
That, I think, would solve my problem.
I have about 4 MBs (yes mega) of unprationed space on the linux HD, could I partition that space as FAT and let Windows dump it's loader on that?

Yeah, I suppose you could give that a go but you'd be advised to try the XP upgrade option with the linux drive as master but upgrade over your existing XP installation on slave then try and get GRUB to work (just reinstall the bootloader from RH cd). I believe the first 524bytes is reserved for the MBR so you should be alright, even if the 4mb is at the end cylinder.

hey
u can change the boot loader by using foll method
first check whether the lba is enabled in the setup
<if not then u have to repartition>

then try to figure out ur partition ids using
#fdisk -l
note down the partitionid for windows, linux boot and root

then run the foll command to modify lilo.conf
#vim /etc/lilo.conf

boot=/dev/hda6 #ur boot partition-id, 6 in my case
map=/boot/map
install=/boot/boot.b
lba32
vga=788
image=/boot/vmlinuz-2.4.7-10 #ur kernel no., this is in my case
label=linux
read-only
root=/dev/hda7 #ur /root partition id, 7 in my case

other=/dev/hda1 # ur windows partition id, 1 in my case
optional
label=Windows

save the changes and then run foll commands
#/sbin/lilo -v
#reboot

ur boot loader willbe changed to lilo

-Sidd

Uh, The RH bootloader calls it DOS, but it boots to windows, just rename the entry as "Windows" if you care aboue what it says

When u boot into linux....go in main menu>>system sumthin >> Kick Start...there insert ur CD 1 of RH....n upgrade ur bootloaders...

When u boot into linux....go in main menu>>system settings or system tools >> Kick Start...there insert ur CD 1 of RH....n check da option for installing whichever bootloader u want