Ubuntu – Clone system and auto replicate the changes

First, my compliments on having a current backup -- you've hit the 90th percentile of diligence right there. Now to proceed, I would do this:

1. Boot from the install CD into the Live Ubuntu envrironment (or if using a server CD, choose the Repair option.)
2. Open a shell window

3. Mount the root drive to /mnt, e.g.

   sudo mount /dev/sda1 /mnt
   

4. Create a second mountpoint, /mnt2 and mount the backup drive to that.

   sudo mkdir /mnt2
   sudo mount /dev/sdb1 /mnt2
   

5. Now restore like this

   for DIR in bin boot etc home lib lib64 opt root run sbin usr var; do
     sudo rsync -aH --delete /mnt2/$DIR /mnt
   done
   

   All of the directories I skipped, dev, sysfs, tmp, etc. should basically be empty.

6. Once the restore completes, try chrooting to /mnt and updating grub.

   for DIR in dev proc sys; do
      sudo mount --bind /$DIR /mnt/$DIR
   done
   sudo chroot /mnt
   update-grub
   

7. Restart

If this doesn't work, then it's time to reinstall and just restore your /home directory & any data files you want.

Yes, this is possible, but you need to know what does not exist any more and what is different so:

1. What does not exist any more:

   rsync --archive --verbose --update --dry-run --delete $szOldServerPath $szNewServerPath | grep "^deleting "
   

   The above command will give you a list of files that do not exist in the new server.

   grep ^deleting because each line prints : deleting ..file..

2. What is different:

   rsync --archive --verbose --dry-run --checksum $szOldServerPath $szNewServerPath
   

   will give you a list of different files (including new files)

Good luck as depending on how long this server has been running you'll get thousands to millions of files that will be different, so whichever system you're going to use, it's never going to be easy as you requested.

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