Backing up an Android device is a broad term, that entails various levels of backup that cover multiple aspects of the data on your Android device, using different tools.
In this post I cover the concept of NANDROID, which refers to a low-level backup of the device, including practically everything that resides within the partitions on the NAND flash of the device – kernel, ROM, apps & data, system data, etc.
NANDROID backup is a snapshot of your device at a specific point in time. As such, it allows restoring the device to the exact state it was when the snapshot was taken. This is a pretty good safety net when experimenting with the device.
NANDROID backup does not include data on the SD card!
A useful reference I used and followed is “How to backup your Rooted ‘Droid – NANDROID & Titanium Backup“, on the AndroidNZ blog.
Performing a NANDROID backup requires a rooted device, with a custom recovery that has a NANDROID backup option, like ClockWorkMod Recovery.
As I rooted my Galaxy S2 by flashing a CF-Root kernel, I already have ClockworkMod Recovery installed (v188.8.131.52), which simply offers a “Backup” function. What follows is a description of the steps to perform a NANDROID backup using CWM on Samsung Galaxy S2 i9100:
- Launch the ROM Manager app
- Select Backup Current ROM
- Enter a name, e.g.
- After confirming, the device will reboot into CWM Recovery and perform the backup, which looks something like this:
- Once the backup completes, the device will reboot, and the backup data can be found on the sdcard, under
- In order to really call this a “backup”, I copied the backup directory from the sdcard to my Dropbox folder (
@Dropbox/Backup/SGS2/ClockWorkMod/2012-09-14-PostRoot), so I don’t end up with a single copy (single point of failure) stored on the device that I’m about to tamper with…
That’s it for the NANDROID backup (pretty simple, eh?).
I don’t know of a way to automate it, but I don’t think it’s needed here, since it’s more of a “restore-point” kind of backup which is a good idea when making “major operations” (like flashing ROMs and kernels).