Full ROM Backup on Unknown Tablet

This is a quick way to perform full ROM backup on tablets. Since those are unknown brand, I have no idea how to "root" them and perform full backup as usual.

Here's how to perform the full ROM backup and restoration on 2 identical (same brand) tablets. (Model M716D running JB 4.0.1)

[ To Backup ]
Start your tablet
Connect the USB cable to tablet
Start command prompt/shell prompt

adb shell
root@android#/ stop zygote [ this one stops android ]
root@android#/ busybox tar -cvf /mnt/sdcard/full_backup.tar /data/*
root@android#/ reboot

[ To Restore ]
Start your tablet
Connect the USB cable to tablet
Start command prompt/shell prompt

adb shell
root@android#/ stop zygote [ this one stops android ]
root@android#/ rm -r /data/*
root@android#/ cd /data/
root@android#/ busybox tar -xvf /mnt/sdcard/full_backup.tar
root@android#/ reboot

[ My Experiment ]

• Make full backup on tablet-1.
• Before reboot, I quit the shell and make a copy to my computer.

1. exit
2. adb pull /mnt/sdcard/full_backup.tar
3. ren full_backup.tar full_backup1.tar
4. adb shell reboot

• After reboot, I start to install games from Play Store.
• Then I try the method above to restore the tablet-1 back to original (first boot assistant). [ success ]
• Make full backup on tablet-2. [ just in case ]
• After reboot, I start to install games from Play Store to tablet-2.
• Before the restore tablet-2, I copy tablet-1's full_backup1.tar to tablet2.

1. adb push full_backup1.tar /mnt/sdcard/

• Then I try the method above to restore the tablet-2 back to original (first boot assistant) using the tablet-1 backup file. [ success ]