USB booting :: Frugal USB boot fails: 'Missing Operating System'

OK, I modified /mnt/sda1/boot/grub/device.map to contain only:

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(hd0) /dev/sda

Then I run grub-install:

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#grub-install /dev/sda1
/dev/sda1 does not have any corresponding BIOS drive.

I also tried changing the device.map to read:

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(sd0) /dev/sda

but got the same result as before. I rebooted into Knoppix 4, mounted the USB thumbdrive, enabled read/write mode, and tried the same command. The result in Knoppix is a little different. First it says:

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Probing devices to guess BIOS drives. This may take a long time.

It takes probably 15 seconds, and then says:

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Could not find device for /boot: Not found or not a block device.

I'm stumped.

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#grub-install /dev/sda1

are you sure that you want to install the primary grub loader (stage 1) into the bootsector of sda1? when not, try

grub-install /dev/sda

for installing it to the pendrives partition table.

#grub-install /dev/sda
/dev/sda does not have any corresponding BIOS drive.

Interestingly:

#mount /dev/sda1 /mnt/sda
mount: /dev/sda1 is not a valid block device

#mount /dev/sda1 /mnt/sda1
mount: /mnt/sda1 does not exist

This is after setting BIOS to boot from CD first, and booting with the USB thumbdrive plugged in. (If I plug the thumbdrive in AFTER booting, and try to mount it manually on /mnt/sda1 it works fine - /mnt/sda1 already exists and I don't have to create it before mounting.)

I think that "does not have any corresponding BIOS drive" and "not a valid block device" are probably the keys here. I just don't know enough to figure out what to do with them.

grub-install looks for the device.map file in /boot/grub. i think you have to tell grub-install where to look for the corresponding usb pendrive directory. try

#grub-install /dev/sda --root-directory=/mnt/sda1

I had the same problem and probably solved in a simpler or more
extreme way. I disconnect every other drive in my system, EXCEPT the USB drive and the CDROM. Then there seemed to be very little confusion about which drive was (hd0) or (hd-whatever). Now I have no more errors from grub and everything is happy.

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