How to change default boot for Grub?

nano_electronix · 09-01-2003, 04:22 AM

Hi all
i was just wondering how could I change the default boot for Grub boot loader.

Currently I have 3 systems on my computer
o Redhat 8
o Win2000 Server
o Win2003 Server

The default boot has been set to be win2003 server when I first installed Redhat 8. I want to change the default boot to win2000 Server. How would i do that?

Any suggestions would be greatly appreciate. Any Links will be very welcomed.

Thanx

James

ppuru · 09-01-2003, 04:27 AM

in /boot/grub/grub.conf, set

default=1

assuming

you have Win2000 is the second in the list of OS entries listed in grub.conf.

nano_electronix · 09-01-2003, 06:18 AM

Thanx mate
Got it working now.

Would anyone also be able to explain exactly how a computer boots?

I know that there is something called the master boot record and that should be on the harddisk somewhere right? where is it on the harddisk exactly, i mean what cylinder and what sector is it on? And say if i am to write a boot loader program, how would i do it (just out of interest)?

This is how I think it works. When the computer boots, it checks the master boot record on the harddisk and decide where to boot next? The next step would probably be that the computer boots up GRUB (the boot loader). Then from GRUB we can choose to boot our chosen operating system.

The thing that i am confused about is, Doesn't window usually overwrites the master boot record? If so, then how come my computer still boots properly after i installed windows on a machine that already has grub and linux running on it?

I am confused. Please shed some light on this

Cheers

James

acid_kewpie · 09-01-2003, 06:51 AM

it's at the very very start of the drive, before the partitions. You really can't ask "how do i write a bootloader" though, that's nuts....

windows will usually overwrite the MBR never know it not to do that, what version are you using?

nano_electronix · 09-01-2003, 07:46 AM

This is my installation procedure

I installed my win2003 server first, because from pass experience i know that windows overwrites the MBR. Then i installed Redhat 8.0 with grub. All that worked fine. The only thing is that there are certain things such as my printer which is not supported on win2003 server (I was just trialing win2003 server).

So then i decided to reinstall my older win2000 server which runs every piece of hardware i have. I would have thought that the MBR gets overwritten, but it didn't, and now i have a working system with triple boot. LOL

Just wanted to know the procedure of the boot process.

Cheers

James