As this is a question that I keep getting over and over, and frankly, it was very confusing to me as well, I thought that it might be worthwhile to help explain what this is and why it is important.
For every device that gets rooted (administrative root access), there are some fundamental steps to the process. Whether you do it the easy way or the hard way, it all comes out the same. This is NOT an explanation of how to do it. If you want to do it the hard way, there are literally dozens of web/video sites out there that will explain. In previous posts, Rod and I have explained the process with DroidMod, which basically does all this for you automatically, in 5 minutes or less.
Backing Up Your ROM and Your DATA
Once you have gained root access to your file system, you will find that the process will also have required the install of an application called SPRecovery. You can't see it in your list of programs, but it is there none the same, as a level below where you can see. The functionality is what gives you the ability to backup every single part of your device to the SD Card, and it backs it up into a directory called Nandroid. You do not have this ability if you do not have root access to your phone. The application also gives you the ability to restore that backup or one that you may have copied from somewhere else, back to your device. This is how a ROM gets moved between devices. Of course the real magic is that folks play with the files in backup and hence change what gets reloaded. Another stellar feature is that you get to decide what gets restored. You can backup your data, but you don't have to restore it. That means you can change the programs and functionality, without over-writing your Data!
In fact, during the process of installing and running DroidMod, it first roots your device, and then immediately performs a Nandroid backup, just in case. If you have used the application, you can go to your SD Card and see the files there. You will notice that the name of the file includes the date when the backup was taken. If you perform a simple restore, it will always automatically take the latest backup.
Performing a Nandroid Backup
Once your device is rooted, you can perform a Nandroid backup at any time, as long as you have space to do so on your SD Card. On my Motorola Droid, each automatic DroidMod backup is consuming approx. 315 MB or so. You can also perform you own full backup, which captures application caches, etc. as well, and for me, that runs around 345 MB. So how do I do it?
- Shut your phone down and boot into Recovery Mode. On the Droid, this is accomplished by holding down the “x†key while powering on. You will then see a triangle with an “!†in the middle. At that point, you press the Volume-Up key and the Camera key at the same time and you will see the Recovery Menu. If you have a DroidMod ROM, it will go directly to the Recovery Menu without the second steps.
- Option 5 is backup/restore. Use the volume-down to move there and camera button to select.
- You will see that you have 4 choices: Simple Nandroid Backup (and Restore), Advanced Nandroid Backup (and Restore). Simple is what DroidMod does automatically for you.
- Advanced Nandroid Backup gives you some additional choices: In addition to Boot, Data, and System, you can also select Cache, Misc, and Recovery. This will give you a complete backup of your device EXACTLY as it is at that moment in time. This menu also let’s you append additional text to the name of the backup. If you get this far, you might be scratching your head: How do I get out of here? In this case, a quick press of the power button is the same as back.
- After you perform your backup, you can go back to the main Recovery Mode menu and chose “reboot system now†and your device will restart as normal.
- What is the point of doing a backup if you don't actually save the files? Yes, they have been saved to your SD Card, but what if you lose your phone? All of that is gone! Please make sure that you connect your device via USB, mount your SD Card, and then copy the \SD Card\nandroid directory entire to your hard disk or somewhere else safe, just in case. It's fast and easy, and very good insurance.
- In fact, if you finally decide to go back to a stock Android 2.0.1 system, this is essentially the process that will be followed.
A Little Help
One of the simple little applications that I have come to rely on is called Quick Boot, a free utility available in the Market. This is nothing more than a small menu that allows you three options: Reboot, Recovery, Bootloader. Reboot is the same as powering off, waiting, then powering on. Recovery will take you directly to the menu described above without any fuss. Bootloader is not something you should mess with in this context. One note: the first time you use this utility it may take 20 or 30 seconds to operate. I found that it was just the very first time. After that, it is very quick and makes this whole process extremely easy.
If you have taken the steps necessary to root your device, this is something that you should be doing on a regular basis. Enjoy!
