grub-setup: warn: Your embedding area is unusually small. core.img won't fit in it.

[MountainX]

I'm trying to install grub2 onto a USB drive.

Here's the error I'm getting:

# grub-install --root-directory=/tmp/temp_liveusb_root16566/usb /dev/sdf
/usr/sbin/grub-setup: warn: Your embedding area is unusually small.  core.img won't fit in it..
/usr/sbin/grub-setup: warn: Embedding is not possible.  GRUB can only be installed in this setup by using blocklists.  However, blocklists are UNRELIABLE and its use is discouraged..
/usr/sbin/grub-setup: error: if you really want blocklists, use --force.

Here's how my USB drive is partitioned:

# fdisk -l /dev/sdf

Disk /dev/sdf: 4009 MB, 4009754624 bytes
23 heads, 23 sectors/track, 14804 cylinders
Units = cylinders of 529 * 512 = 270848 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disk identifier: 0x00000000

   Device Boot      Start         End      Blocks   Id  System
/dev/sdf1   *           1       14804     3915646+  83  Linux

Any ideas?

[dcstar]

I'm trying to install grub2 onto a USB drive.

Here's the error I'm getting:

# grub-install --root-directory=/tmp/temp_liveusb_root16566/usb /dev/sdf
..........

Any ideas?

/tmp is a System folder with various restrictions and limitations, why are you using it?

[john newbuntu]

Yeah, using the local /tmp dir is one interesting thing. If you are just trying to install grub2 to your USB, you would normally mount it and use the mountpoint or a permanent sub-directory under the mountpoint for the install.

For example, say /dev/sdf is mounted under /media/myusb, then
"sudo grub-install --root-directory=/media/myusb /dev/sdf"
should install grub2 to the MBR of your USB drive and the grub files would go under /media/usb/boot/grub/.

The other issue here I think is that your post MBR region is small enough to embed core.img. With a logical geometry of 23 sectors/track and your partition starting at cylinder 1, I get a feeling that you do not have enough LBA's for embedding that file. To confirm it, could you please post the output of "sudo fdisk -lu /dev/sdf".
You need around 32KB following the MBR for embedding, which means you may have to resize sdf1 or use blocklists or repartition your drive.

[MountainX]

SOLVED:

I theorized that the problem was the flash drive's geometry. See the fdisk printout and note:

23 heads, 23 sectors/track

I ran fdisk again, but this time I made the first partition start at 2 instead of the default 1. (I did not change the geometry.) This gave a little more room on the flash drive in front of the partition. Bingo, problem solved.

(So it didn't have anything to do with using /tmp.)

Postscript:
This got me thinking about partition alignment on my flash drive. The drive is a Patriot XT 4GB. I think it uses 128K erase blocks? (reference: http://thunk.org/tytso/blog/2009/02/...se-block-size/)

As an experiment of sorts, I decided to redo the partitions and for 128k alignment. Here's how I did it in a nutshell. It works, although I did not do any benchmarking.

~# fdisk -l
~# mount -l
~# umount /dev/sdf*
~#  fdisk -H 224 -S 56 /dev/sdf
Command (m for help): p
Command (m for help): o
Command (m for help): p
Command (m for help): n
Command action
   e   extended
   p   primary partition (1-4)
p
Partition number (1-4): 1
First cylinder (1-624, default 1): 
Using default value 1
Last cylinder, +cylinders or +size{K,M,G} (1-624, default 624): 
Using default value 624
Command (m for help): x
Expert command (m for help): b
Partition number (1-4): 1
New beginning of data (56-7827455, default 56): 256
Expert command (m for help): r
Command (m for help): p
Command (m for help): u
Command (m for help): p
Command (m for help): a
Partition number (1-4): 1
Command (m for help): w
~# mke2fs -t ext2 -E stripe-width=32,resize=165G /dev/sdf1
~# tune2fs -c 0 -i 0 /dev/sdf1

references:
http://www.ocztechnologyforum.com/fo...226#post373226
http://www.patriotmemory.com/forums/...ead.php?t=3696
and, of course:
http://thunk.org/tytso/blog/2009/02/...se-block-size/

[MountainX]

The other issue here I think is that your post MBR region is small enough to embed core.img. With a logical geometry of 23 sectors/track and your partition starting at cylinder 1, I get a feeling that you do not have enough LBA's for embedding that file. To confirm it, could you please post the output of "sudo fdisk -lu /dev/sdf".

You were right. I confirmed by repartitioning starting at cylinder 2, as I posted above. Thanks for your info.

[ftzdomino]

I had this problem on a Dell server. It was fixed by deleting the Dell utility partition (which is worthless) and re-running grub-setup. My theory is that the Dell utility partition starts at too low of a sector to give grub2 enough room to install.

[HittingSmoke]

Just an FYI for anyone coming to this post from Google as I just did.

I ran into this problem today trying to install GRUB on my 16GB USB thumb drive. After reading this post I installed gparted in Ubuntu 10.04 and move the start of the first partition up 1MB.

Fixed the problem in two minutes without reformatting the entire disk.