Changing boot order - Grub error 17 / removing grub

[fatandwheezing]

New to these forums, hope somebody on here can help out as I'm at a bit of a loss.
Hopefully I can explain my problem clearly enough on here.

I am upgrading a system to have encrypted disks, it's a two disk system, so I want the BIOS to look at /dev/hdb first to unlock it, then it should reboot, see that isn't a system disk and try to boot /dev/hda. Then that gets unlocked, and the system boots.

After unlocking hdb I get a Grub error 17.
I can't edit Grub to look at hda as on normal boot it hasn't been unlocked yet, so it can't see the file system at that point.

I reformatted an old XP disk as hdb, and it worked fine, but I'd rather not install windows every time, just to reformat it as ext3.

Is there a simple way of clearing the boot sector of hdb?

Thanks

Bill

[fatandwheezing]

Should have added I have an old debian installation (sarge), have tried it with a recent distribution as well with no luck.

[oz]

Is there a simple way of clearing the boot sector of hdb?

Welcome to the forums!

Are you sure it's hdb? Most new kernels today see all hard drives as scssi, making them sda, sdb, etc.

To clear the MBR (master boot record) only, leaving partition tables alone:

sudo dd if=/dev/zero of=/dev/sdb bs=446 count=1

or...

sudo dd if=/dev/zero of=/dev/hdb bs=446 count=1

(remove the sudo part of the command if you don't use sudo.

[fatandwheezing]

Thanks for replying - I'll try that and let you know if it works.

It's quite an archaic system, pretty old motherboards with no serial connector, so it's still the hda/hdb convention.

[fatandwheezing]

Well that didn't work - the BIOS still saw something it didn't understand and just froze.

Got the system working by putting a windows boot loader on, and then adding the EXT3 filesystem. Ghosting all that, so shouldn't be a problem now.