Android Enthusiasts Stack Exchange is a question and answer site for enthusiasts and power users of the Android operating system. It only takes a minute to sign up.
Sign up to join this community
I noticed that for some system apps (for example chrome, which is preinstalled by default on my device) I can't do adb backup . Doing so results in the 47 bytes dummy .ab file. I checked in manifest they have allowBackup="true".
Eg for chrome this is:
allowBackup="true" backupAgent="org.chromium.chrome.browser.ChromeBackupAgent" extractNativeLibs="false" fullBackupOnly="false".
Why this is happening? How can I backup such apps' data without root? PS: Helium backup doesn't show system apps.
I found the reason in logcat while performing an backup:
BackupManagerService: Package com.android.chrome is key-value.
By default for abd backup keyvalue backups are disabled:
"/system/bin/bu" (the command that is called on-device by adb backup) help text:
-keyvalue|-nokeyvalue: include apps that perform key/value backups.
(default -nokeyvalue)
Therefore you need to include the -keyvalue option to create a chrome backup:
adb backup -keyvalue -f chrome.ab com.android.chrome
This creates a backup file that contains only the chrome settings (no cache files, cookies, local data ...)
