There are three directories that exist on the USB stick.

The main directory is called boot

Two sub-directories are:
custom & grub

Here is the contents inside the grub directory
[RHEL6.0 - 64bit] grub # ls -l *
-rw-r--r--. 1 root root 30 Sep 23 15:08 device.map
-rw-r--r--. 1 root root 0 Sep 23 15:08 device.map.backup
-rw-r--r--. 1 root root 13204 Sep 23 15:08 e2fs_stage1_5
-rw-r--r--. 1 root root 12516 Sep 23 15:08 fat_stage1_5
-rw-r--r--. 1 root root 11748 Sep 23 15:08 ffs_stage1_5
lrwxrwxrwx. 1 root root 8 Sep 23 15:08 grub.conf -> menu.lst
-rw-r--r--. 1 root root 11756 Sep 23 15:08 iso9660_stage1_5
-rw-r--r--. 1 root root 13220 Sep 23 15:08 jfs_stage1_5
-rw-r--r--. 1 root root 235 Sep 23 15:08 menu.lst
-rw-r--r--. 1 root root 11940 Sep 23 15:08 minix_stage1_5
-rw-r--r--. 1 root root 14300 Sep 23 15:08 reiserfs_stage1_5
-rw-r--r--. 1 root root 1341 Sep 23 15:08 splash.xpm.gz
-rw-r--r--. 1 root root 512 Sep 23 15:08 stage1
-rw-r--r--. 1 root root 113044 Sep 23 15:08 stage2
-rw-r--r--. 1 root root 12008 Sep 23 15:08 ufs2_stage1_5
-rw-r--r--. 1 root root 11364 Sep 23 15:08 vstafs_stage1_5
-rw-r--r--. 1 root root 13932 Sep 23 15:08 xfs_stage1_5


Contents of grub.conf:

[RHEL6.0 - 64bit] grub # cat grub.conf
default 0
timeout 60

title Custom Recovery
kernel /boot/custom/vmlinuz load_ramdisk=1 prompt_ramdisk=0 ramdisk_size=92160 ramdisk_blocksize=1024 root=/dev/ram0
initrd /boot/custom/custom.img

where is:

in the menu.lst on the stick? Next, explore with fdisk (and the stick plugged in, mounted is not an issue) with

fdisk -1

This should display every disk on the system (including the stick) - check if the boor partition (or only partition) is at all bootable...

As soon a the system on the stick boots, the stick becomes the root drive, hence...

We'll get there...

Here is the output of fdisk -l while the server is booted and the USB stick is plugged in a mounted.


# fdisk -l
Disk /dev/sda: 160.0 GB, 160041885696 bytes
255 heads, 63 sectors/track, 19457 cylinders
Units = cylinders of 16065 * 512 = 8225280 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disk identifier: 0x000b0156

Device Boot Start End Blocks Id System
/dev/sda1 * 1 64 512000 83 Linux
Partition 1 does not end on cylinder boundary.
/dev/sda2 64 19458 155777024 8e Linux LVM

Disk /dev/dm-0: 53.7 GB, 53687091200 bytes
255 heads, 63 sectors/track, 6527 cylinders
Units = cylinders of 16065 * 512 = 8225280 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disk identifier: 0x00000000

Disk /dev/dm-0 doesn't contain a valid partition table

Disk /dev/dm-1: 2113 MB, 2113929216 bytes
255 heads, 63 sectors/track, 257 cylinders
Units = cylinders of 16065 * 512 = 8225280 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disk identifier: 0x00000000

Disk /dev/dm-1 doesn't contain a valid partition table

Disk /dev/sdb: 80.0 GB, 80022167552 bytes
255 heads, 63 sectors/track, 9728 cylinders
Units = cylinders of 16065 * 512 = 8225280 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disk identifier: 0xaabda1e2

Device Boot Start End Blocks Id System
/dev/sdb1 1 2 16064+ 6 FAT16
/dev/sdb2 * 3 5 24097+ 83 Linux
/dev/sdb3 6 9728 78099997+ 83 Linux

Disk /dev/dm-2: 103.7 GB, 103712555008 bytes
255 heads, 63 sectors/track, 12608 cylinders
Units = cylinders of 16065 * 512 = 8225280 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disk identifier: 0x00000000

Disk /dev/dm-2 doesn't contain a valid partition table



The /dev/sdb is my USB device.

Hmmm, a bit "messy" if I may say...

Nonetheless, it seems (from what I can see here) that ./dev/sdb2 is bootable...this should be set in the grub on the stick. By the way, I'm somewhat allergic to the fat16 entry...this is not the best setting you could have...but, if there is data on the disk, you're stuck with that...

An example of a better setup would be (as a suggestion)

Where s is start, e is end and nnn is the amount of blocks. Keep all the system types on Linux, if possible. Unless the stick is to be accessible by a (very-very) old win95 PC...

The grub needs IMHO to find ./dev/sdb2 as boot partition...this needs to ne an entry in the grub on the stick. And, of course, grub needs to be in the partition with the MBR...but, you know this. On the down side...I suspect the MBR to be in the fat16 partition, in that case...the boat is sunk...you may have to repartition the stick...

Grtz!

Thor

Found the issue. It was with my init file location. Once I placed init inside / on my cdinit image, everything booted up.

Thanks so much for your help.