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I can understand needing a boot manager when you have seperate os on the same drive.

But what I have is 2 drives with Ubuntu on both, I wanted to boot them independent of each other, using the bios to set boot.

But thanks to GRUB, it jumps in and takes control making one drive the master and the other a slave to where if the master drive goes bad the slave is unbootable and useless?????

What I would like to do is get rid of GRUB completely, and use the BIOS to set boot. Is that possible?

Thanks!

UPDATE When I disconnect the drive GRUB has made the master and try and boot with the slave I get this,

error: no such device:
error: unknown filesystem.
Entering rescue mode...
grub rescue>

How can I fix that? I do not mean to make post sound like ranting and raving, it's just I am mad how GRUB screwed this up! Thanks for your help!

Cougar
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2 Answers2

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If you remove all other drives during Ubuntu installation, then Grub should only be able to install itself to the one drive that it can see. You can then use the BIOS to choose which drive to boot from.

Be careful about upgrading from one version of Ubuntu to another with this setup.

Matthew
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The main program grub exists in /boot/grub/ ; though the MBR or master boot record (first 512 bytes of a drive; your BIOS config will dictate which drive's MBR is used) contains a pointer to this location. The error message you have "no such device" is because you've probably removed the driver which contains /boot/grub/ or where the pointer points to.

It sounds like you want each drive's MBR to point to it's own drive's first sector. So do that, using grub-install

Refer https://help.ubuntu.com/community/Grub2/Installing ("Reinstalling GRUB 2 from a Working System" section)

sudo grub-install /dev/sdX  # Example: sudo grub-install /dev/sda

where sdX will be replaced by your drive details (eg. sda). As the MBR relates to a drive, you don't use partition but drive (thus it's sda/sdb/..) Do this for each drive if necessary.

You can use blkid to get details of what sdX should be if necessary.

Note: Even if you only have a single OS installed on a single drive, grub is still useful. If something goes wrong with a kernel upgrade or change you made; you can use grub to boot an older kernel, boot to runlevel 1 or add kernel parameters to solve issues. It's really useful to fix things

guiverc
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