Grub error 21 when external hard drive is disconnected, Grub runs fine when connected

[madcow53]

Hello everyone,

I apologize if this question has been answered, but I have not found a specific answer to my situation. I am running Suse Linux 10.1 on my computer through my external hard drive. Everyone works fine when my external is connected, grub loads, I can boot into either suse or Windows XP Pro SP2.
The problem is when I disconnect my external, it gives me the cannot run grub loader error 21 and I cannot run any OS.

Now, I suspect that this is because the grub loader has been installed on my external hard drive and thus why it can't boot when it's not connected. I have tried to reinstall GRUB on the MBR of my internal drive. When I do this through the Suse 10.1 Install CD1, it gives me an error that it cannot perform the operation. I can find the exact error if needed.

I have also tried to switch my external hard drive up in the booting order, but then I get the cannot load OS error. (I think I might be doing these things out of order)

Since I don't want to screw up either partition, I wanted to ask if anyone has encountered this problem and knows how to solve it. Also, does anyone know a good source of information to become more familiar with the whole booting process (MBR, where it is located, how the windows one can be accessed)?

Thank you very much,
Mauricio

[Amano]

One thing to do is to get Grub out of the MBR and to use the Windows bootloader; you would need to find some way to reinstall Grub to the external hard drive where the linux kernel is located (I'm new to Linux, so I can't help you there). Once Grub is on the external drive and out of the MBR, you need to get the Windows bootloader in there and once that's done, you should download a program called 'bootpart'. It configures the Windows boot.ini file so that you can find and list other OSes on startup.

[devils casper]

hi madcow53 !!!

Welcome to the LinuxForums !

Now, I suspect that this is because the grub loader has been installed on my external hard drive and thus why it can't boot when it's not connected. I have tried to reinstall GRUB on the MBR of my internal drive. When I do this through the Suse 10.1 Install CD1, it gives me an error that it cannot perform the operation. I can find the exact error if needed.

Boot Loader is installed in the Internal Harddisk. when you unplug external disk, GRUB couldn't fine stage1 and threw errors.

Since I don't want to screw up either partition, I wanted to ask if anyone has encountered this problem and knows how to solve it. Also, does anyone know a good source of information to become more familiar with the whole booting process (MBR, where it is located, how the windows one can be accessed)?

boot up from Windows Installation CD and select Reapi(r). type 'Fixmbr' on command prompt. this command will remove GRUB from internal disk and you will be able to boot up Windows.
now, plug-in External Harddisk and boot up from SuSe Installation CD/DVD and select 'Boot from Harddisk' option. boot up SuSe and install 'Boot Loader' ( GRUB ) in MBR of External Disk through 'Yast'.





Casper

[madcow53]

Thank you for your prompt responses.
I went ahead and did the fixmbr and now I am able to run Windows when my external is disconnected. Unfortunately, now I can't get GRUB to install correctly into my external.

I boot up my computer into my SUSE Linux CD1 and then I go to install and then (eventually) to repair installation. Then I choose the automatic repair and when I get to the boot loader section, I try to install GRUB into the boot sector of my external. Then I get this error:
setup --stage2=/boot/grub/stage2 (hd1,5) (hd1,5)

cannot find selected device

So I decide to go to the recovery console from the SUSE Linux CD to try to install grub manually. I type grub and then I did setup (hd1) (hd1,5) and it seemed to have installed correctly, but unfortunately I can't get grub to show up at startup unless I boot directly from the external hard drive. Is GRUB broken? Am I missing something here? Let me know if you need more info.

Thanks!

[madcow53]

hd1: refers to the external drive
(hd1,5): refers to the linux root partition

[devils casper]

you have set External Harddisk as 'first boot device' in BIOS to boot up Linux OR you can use Smart boot Manager. is External Harddisk booting up on setting it as 'first boot device'?





Casper