Q: How to move filesystems (including root and boot) from one drive to another

[Philip Prindeville]

I recently decided that my build server was running too slow (disk 
bound) and went out and bought a 3ware 9650SE controller and disks.

Got the array configured as a single RAID 5 logical unit (yes, I know, 
RAID 5 has slow writes...) and ran fdisk on the unit to create partitions.

I formatted the partitions...

I mounted each of the partitions and did the following:

# cd /old-fs-mnt-point
# find . -depth -mount -print0 | cpio --null -pdv /new-fs-mnt-point

then I ran:

# mkswap ...
# hal-device | less

to get the UUID's.  I edited the new /boot/grub/grub.conf and /etc/fstab 
and rebooted.  Oops.  Didn't quite work.  Needed to change the BIOS 
drive assignment order so that the array was now /dev/sda.

Rebooted.

System hung: forgot to install the boot blocks.

Hmmm...  Tried to run "install-grub /dev/sda" from the Live CD, but that 
didn't work.  Something about not being able to figure out the BIOS 
drive number... don't understand why that's relevant, but that's a 
different story...

So I reran the installer, using a small partition that I had left for 
whatever... and it wrote the boot blocks and MBR.

Editted /boot/grub/grub.conf to change back the default to what I 
wanted... and rebooted.

Now the system hangs at:

Red Hat nash version 6.0.52 starting
Unable to access resume device (/dev/sda3)
mount: error mounting /dev/root on /sysroot as ext3: No such file or
directory
setuproot: moving /dev failed: No such file or directory
setuproot: error mounting /proc: No such file or directory
setuproot: error mounting /sys: No such file or directory
Mount failed for selinuxfs: on /selinux: No such file or directory
switchroot: mount failed: No such file or directory



This is FC9 (updated) x86_64 on a Phenom/NVidia MB.

What have I forgotten?

Moving filesystems used to be a lot easier (these are plain ol' ext3 
filesystems... I'm not using LVM)... and I thought the whole UUID 
support was to simplify moving drives around, etc.

Doesn't seem to be the case.  (Ah, for the days when just about 
everything that caused a booting system to hang was pretty much 
self-evident and transparent...)

There's a certain amount of tweaking I've done of the configuration, the 
rpm's I've installed, accounts created, kernel variables that I tune... 
it's kind of painful to have to do a reinstall from scratch.

Also, I wanted to peek inside the initrd.*.img files and see if there 
was anything in there choking up... but I couldn't figure out how to 
mount them as loopback filesystems.

Any revelation of these mysteries appreciated.

-Philip