I have come across a way to make NANDROID back without booting into recovery at all! You can easily make the backup while running your phone and even cooler, you can schedule backups at any time of the day and thus you can experiment all you want with your Xperia L
The credit goes to the developer and this is his thread which has all the details :
Nandroid backups are usually performed in recovery mode. This means you would have to turn off your phone and reboot in recovery mode, which wastes a whole lot of time rebooting and a lot more time offline. For me, this has been a killer as I do regular nandroid backups. Having to reboot in recovery and finding missed calls, sms from my wife and friends is totally not accepatable for me. So, I set to develop an online nandroid backup tool, namely Online Nandroid, which can do nandroid backups without switching off my phone.
Today, I am releasing it to public, as it may serve good for some others too. Originally I developed Online Nandroid specifically for Xperia devices, but now I am releasing it for all android devices.
This tool, eventhough called "Online Nandroid", does not upload/save backups to any online/cloud services. Online here means that it does backup while phone is live or still running Android.
The short name onandroid is meant to be pronouced as o-nandroid or o'nandroid and NOT on-android.
1. Rooted android phone
2. A terminal emulator installed on phone
3. Latest version of Busybox
4. A working CWM, TWRP or 4EXT based recovery installed
5. Some patience
1. Download and copy zip file to SD card
2. Reboot into recovery
3. Choose install zip from SD card, select zip and flash
1. Open terminal emulator
2. Type su to obtain root
3. Type onandroid
4. Wait and watch
Issue Tracker: http://bit.ly/OnlineNandroid-issues
Older Versions: http://bit.ly/OnlineNandroid-downloads