Article

After installing updates on SLES/OES servers we have had issues where the server doesn't boot. The console comes to:

"No root device found; exiting to /bin/sh
sh: "

Usually the console is unresponsive.

This is because the kernel was upgraded and a new initrd was created but it was not created with EVMS support (for some reason, not sure why, wonder when Novell/Suse is going to fix this??).

Mostly copied from:
http://www.lotterer.net/blog/en/51-sles10-with-evms-missing-root-past-boot

# boot with the SLES10 AMD64/EMT64 CD1 or DVD. Use the correct arch, 32 or 64 bit.
The link says to use rescue mode of a SLES cd, but I like using RIPLinux 7.2. (the newer versions don't support evms). It has a smaller footprint so it boots faster.

# boot to rescue mode and enter "root" at the prompt. You will be at a command prompt.

#This isn't needed, but I left it just in case.
# sidenote: to access a CD/DVD at this point, use
# modprobe ide-cd; mkdir -p /mnt; mount /dev/hda /mnt

# probe EVMS information
echo "probe" | evms -s

# query devices
echo "q:d" | evms -s

# query volumes, this should display the name your root container
echo "q:v" | evms -s

#If you know your mount points, you won't really need to use the commands above.
# mount root (note the comma in the mount command after the "sys_lx")
This should be mounting your root files system.
echo "mount:/dev/evms/lvm2/system/sys_lx,/mnt" | evms -s

If you have /var as a separate partition you'll want to mount it also.
Ex:
mount /dev/evms/lvm2/system/var /mnt/var
#and if boot is separate: (it should be)
mount /dev/evms/sda1 /mnt/boot

# you should see your valuable data on the old root
ls -l /mnt/

# turn your old root into the current root
mount -t proc none /mnt/proc
mount -o bind /dev /mnt/dev
chroot /mnt /bin/bash
#you must choose the correct RIP kernel for your architecture.
#you may get an error here if you did not choose the correct arch

# create a new EVMS ramdisk
/sbin/mkinitrd -f evms

#exit chroot
exit
#dismount volumes
umount /mnt/boot
umount /mnt/var
umount /mnt

# shutdown properly and reboot
init 6
or reboot
#or press CTRL+ALT+DEL