Adb backup does not work

Question

I need help from you guys, because I don\'t know what I did wrong with adb backup.

I want to backup my Samsung Galaxy S3 LTE (GT-I9305) without root. I googled it and fou

Answer 1

This just worked using Ubuntu 15.10 ("wily") to backup a Galaxy SM-G900V running Android version 6.0.1.

Installed using:

sudo apt-get install android-tools-adb

Then I ran the following from the command line (without 'sudo'):

adb backup -apk -shared -all -f backup.adb

Result:

user@hostname:~/droid$ ls -lah
total 1.2GB
drwxrwxr-x  2 user user 4.0BK Mar  6 18:43 .
drwxr-xr-x 52 user user 4.0KB Mar  6 17:40 ..
-rw-r-----  1 user user 1.2GB Mar  6 18:29 backup.ab

Thank you "NG". I was beginning to think my phone was borked.

Forgot to add: Running adb version: Android Debug Bridge version 1.0.31

Answer 2

Seem not all apps can be backed up. Android apparently allow apps to disable backup :(

https://developer.android.com/guide/topics/manifest/application-element.html (search for allowbackup)

Answer 3

Just incase anyone is still having trouble - In windows, I found putting the quotes around only the directory, for example "C:\Users\NAME\backup.ab" worked.

Answer 4

The problem is the adb version of your PC. Using adb version 1.0.31 the backup/restore will be sucessfull.

More info on: https://android.stackexchange.com/questions/83080/adb-backup-creates-0-byte-file-prompts-for-current-backup-password-even-though and How to downgrade my SDK Version?

If your device has an adb version prior to 1.0.31, then you must use an adb version of 1.0.31 on PC. Versions of adb 1.0.32+ broken the backwards compatibility. Source: Issue 208337

Answer 5

Rather than trying to find an old version of adb, it's easier to add quotes to the arguments to adb backup :

adb backup "-apk -shared -all -f C:\Users\NAME\backup.ab"

Answer 6

adb backup -all worked partway for me, then froze. using all the options NG gave prompted me to unlock and confirm, but then immediately exited without giving me the chance. using -system alone gave a useless 46-byte "backup".