UUIDs and PARTUUIDs cloning for backup recovery

[John Griessen]

Hi,

I once used grub1 to clone disks to multiple other disks and after each
cloning run with rsync a script changed fstab to match the device it was on
and I was ready to boot from 3 or 4 places on the same machine, or over ssh to 
another
machine.  I occasionally had wrong boot attempts because of changing /dev/sdc 
vs. /dev/sdb
definitions, but that was not too often and fairly easy to fix.

How would I get that function back today where debian and the rest all use 
UUIDs and PARTUUIDs?

Does anyone have a good script for it?  It seems so complicated now.

I recently tried booting an rsync copy of my main workstation computer with two 
screens
and lots of engineering tools and data installed so it has a size of 45GB.
I was starting from a mdadm raid1 boot to /.  I copied that with rsync, and 
booting
the copy on a single hard drive, grub2 gives me kernel panics
and cannot utilize a hand written grub.cfg menu entry like this:

menuentry 'Debian stretch/sid Linux 4.7.0-1-amd64' --class debian --class 
gnu-linux --class gnu --class os {
  load_video
  insmod gzio
  insmod part_msdos
  insmod diskfilter
  insmod mdraid1x
  insmod ext2
  set root=UUID=87d52f42-838c-4418-a37e-f0d0a63ed8ed
    echo 'Loading Linux 4.7.0-1-amd64 ...'
    linux /boot/vmlinuz-4.7.0-1-amd64 
root=UUID=87d52f42-838c-4418-a37e-f0d0a63ed8ed  ro rootdelay=20
    echo 'Loading initial ramdisk ...'
    initrd /boot/initrd.img-4.7.0-1-amd64
}

I ran
sudo dpkg-reconfigure grub-pc

Do I need to create a different initrd.img as if it was on a single disk?  Do I 
need to get a chroot
on the copy's / to run to do that?

Should I be using
set  root=PARTUUID=f2ce6af6-01
?