grub-probe: error: Cannot find a GRUB drive for /dev/sdb1. Check your device.map.

[Daryl Styrk]

I am in the process of installing the new knoppix to a thumb drive from
Lenny. Following the tutorial from
http://www.knoppix.net/wiki/USB_Based_FAQ

I get as far as installing grub and it bails.

T61:/mnt# mkdir -p /mnt/boot/grub
T61:/mnt# echo '(hd0) /dev/sda' > /mnt/boot/grub/device.map
T61:/mnt# grub-install --root-directory=/mnt --no-floppy '(hd0)'
grub-probe: error: Cannot find a GRUB drive for /dev/sdb1. Check your
device.map.


I don't completely understand what I'm doing here so I also try /dev/sdb
to see what happens..

T61:/mnt# echo '(hd0) /dev/sdb' > /mnt/boot/grub/device.map
T61:/mnt# grub-install --root-directory=/mnt --no-floppy '(hd0)'
grub-probe: error: Cannot find a GRUB drive for /dev/sdb1. Check your
device.map.

/usr/sbin/grub-install: line 374: [: =: unary operator expected
The file /mnt/boot/grub/stage1 not read correctly.


I googled around a bit, and I can't pin down the same error for what I'm
doing although there are a few that are fairly close. I see there has
been a bug filed against grub already. http://tinyurl.com/aug67n


Any ideas on how I can proceed with the knoppix installation?

[Jimmy Johnson]

The basics, did you prepare the drive to be booted, did you make a
partition active/bootable? Just install "gparted" to look at the drive
and as long as you don't have it mounted you can make changes,
"gparted" is in the Lenny repos.

If I understand you correctly, I need to make a special partition on the
thumb that is flagged as the boot partition and install grub to that? I
would have thought that would have been mentioned in the tutorial. Or
possible assumed knowledge. I suppose I'm not understanding the plainly
written English correctly.. (I've been know to be an idiot before!)

What I'm saying is a drive has to bootable in order to boot.
If you want it all on one partition or more than one partition, it don't
matter as long as the first partition is made bootable.

"Create a file system on the partition. You can use an existing VFAT
filesystem (to keep compatibility with Windows/DOS). Regardless, make
sure the partition type (set when you partition the drive) matches the
filesystem you install. (If they differ, grub-install will fail with a
confusing message "file ...boot/grub/stage1 not read correctly".)
Assuming you settle on an ext3 filesystem: "
I thought simply deciding on using the entire drive would have
eliminated the above warning. Thinking along the lines of the debian
installer, "All files in one partition (recommended for new users)"
Trying to keep this K.I.S.S.

If you put it all on one partition it still needs to be bootable and
gparted will do that for you and you don't need to reinstall to do this,
just open gparted and go to flags and check boot for the first
partition, even if it only has one partition.

I followed the suggestion of mke2fs -j -I 128 /dev/sda1 per the below...
"Warning: Newer versions of mke2fs now create filesystems with inode
sizes of 256 by default (instead of 128), which is causing compatibility
issues with a lot of ext2/ext3 tools out there. If you want to be able
to access your files from windows (using explore2fs for instance) make
sure you do this instead: "
And at the grub stage I just went word for word on down..
So perhaps I create 2 partitions on the thumb, say a 512M for /boot
flagged boot and the difference for / ?

If you want, but it's not needed, like I say it can all be on one
partition, just make sure it is active/bootable.

I hope that helps.
--
Jimmy Johnson

Bakersfield, CA. U.S.A.
Registered Linux User #380263
K.I.S.S. (Keep it simple stupid)

[Emanoil Kotsev]

Post by Jimmy Johnson

And at the grub stage I just went word for word on down..
So perhaps I create 2 partitions on the thumb, say a 512M for /boot
flagged boot and the difference for / ?

If you want, but it's not needed, like I say it can all be on one
partition, just make sure it is active/bootable.
I hope that helps.

I'm not really sure that partitions on modern pc has to be made bootable for
grub to work

just run grub

inside the grub console setup your root partition

for instance first partition on first drive is set with

root(hd0,0)

and after this just setup grub on this partition

setup(hd0)


it can't be made more simple I think

regards

[Thorny]

Post by Emanoil Kotsev
I'm not really sure that partitions on modern pc has to be made bootable
for grub to work

Correct, GRUB doesn't care if a partition is marked as the active
partition(bootable), that is something that matters to a DOS(Windows) MBR.

To the OP, Daryl, did you follow the steps in the FAQ you mentioned
exactly as they were written, it's not clear from your post that you
copied the GRUB stage 1, 1.5 and 2 files to the drive.