I like the idea to create backup without any other tools and without require root - so "adb backup" seems to be the perfect solution.
But for some strange reason it creates just almost empty backups for some apps.
The command I use is:
adb backup -f ${APP}.ab -apk -share -nosystem ${APP}
Around 50% of my apps are suffered. I can't see any rule. Neither this are just payed apps, nor it depends whether they are from playstore or FDroid. What can be the reason for that?
I use that one on my ubuntu linux machine:
Android Debug Bridge version 1.0.39
Version 1:8.1.0+r23-5ubuntu2
Installed as /usr/lib/android-sdk/platform-tools/adb
Tested different parameters - no change.
I created a script that create backup for each user app (so skip these in priv-app and system folders).
Maybe that is useful for others. A complete backup is not very usefull, as there is no command to restore a selection out of the backup - all or nothing.
The script has two issues:
not all apps get backup
there is need to unlock for each app (tip on phone to confirm)
To create a list I used that command:
adb shell pm list packages -f | grep -v priv-app | grep -v '/vendor' | grep -v '/system' | rev | cut -d = -f 1 | rev | sort
Edit:
Think I could find the reason. In each APK there is an AndroidManifest.xml file that can/must (?) have a setting:
android:allowBackup
Whether to allow the application to participate in the backup and
restore infrastructure. If this attribute is set to false, no backup
or restore of the application will ever be performed, even by a
full-system backup that would otherwise cause all application data to
be saved via adb. The default value of this attribute is true.
Bummer!
I think two ways to workaround that. Either change that on phone (which might be not possible or need root) or to manipulate that before installing it.
It that will work I guess it has to repeat after each update.
Anyone has a solution?
Are backups without root/google cloud possible?
You can follow these steps:
copy the app's apk from the device to your computer
decompile the apk using apktool (using "d" option)
modify the allowBackup attribute in the AndroidManifest.xml and set it to true
recompile the app using again apktool (this time with "b" option)
install the recompiled app
use adb command you posted to perform the backup
I spend lots of time in finding a way to do it and can for sure say:
In 2023 with recent android versions (12 and 13) there is no way in getting app data backed up without root.
Even the mentioned apktool method doesn't work because android uses signed apks now.
Even if you try to bypass this using a custom certificate/keystore you'll need to uninstall the original app and then the app data is most certainly gone.
I have in my application Android manifest:
android:allowBackup="true"
But in spite of using an Android 8 device the backup does not work until I manually put in the console:
adb shell bmgr backup #pm# && adb shell bmgr run
and...
adb shell bmgr fullbackup <PACKAGE>
as says the Android developers guide to test a backup.
I have tested so many devices and when I put this in console it starts to work fine and I can uninstall and install the application from Google Play without losing the SharedPreferences. But if I don't write this in my Android Studio console with the device connected, the backup doesn't work.
It's strange because many other applications restore their data, so I think that the device settings are ok and I am missing something in the code.
This are my build.gradle sdk specifications
def valueMinSdkVersion = 15
def valueTargetSdkVersion = 28
Thank you so much.
Mauricio Güell
use these 2 in your manifest:
android:allowBackup="true"
android:fullBackupOnly="true"
why we use fullBackuoOnly?
Android versions before Marshmallow had a backup system that required a significant developer effort to implement. If you implemented that system, but you want your app to use the new backup system on devices where it's available, you can set this flag to disable the old backup system only on devices where the new system is available. This is better than removing your implementation of the old backup system, because older devices will continue to back up with the old system. If you didn't implement the old backup system, or will remove it from your app, you don't need this flag.
I removed an app existing in data folder of my device using adb shell , but while installing the app from my code in device its showing error that can not install over already existing signature. As of now, no app or package exist in my device of the same application.
Try to install it with help of "pm install" (not adb install) and post error text here. Possibly it's not fully uninstalled (which is ridiculous but possible in some cases). Also you need to be sure that app signed with production key and (if it's preinstalled app) with vendor key. In other case it's work would be unpredictable.
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 found Full Android Backup with SDK Manager. I installed all i need for this like Java Development Kit 8 version 66 (JDK 8u66 x64) and Android Studio which contains SDK Manager. Then they sad i should download the Google USB Driver. I downloaded it but nothing happened. I thought it should work now and then I went to C:\Users\MYNAME\AppData\Local\Android\sdk\platform-tools and left-clicked adb whilst holding Shift. Then I clicked "Open command window here". After this I typed in "adb devices" and it said:
List of devices attached
3204cfaaf8611199 device
Then I typed in:
adb backup -apk -shared -all -f C:\Users\NAME\backup.ab
It said
Now unlock your device and confirm the backup operation.
I did this and my Smartphone opened "Full Backup" and then I was able to set a password for the backup. I don`t need a password and I just clicked "Back up my data" Then it went back to my homescreen and said "Starting backup..." as a toast message and immediately after this it said "Backup finished" and created a backup file with 40 bytes. I don't know what I should do now.
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"
The line, which correctly invokes adb, needs to look like this at my side:
adb backup "-apk -obb -shared -all -system" -f phone-20180522-120000.adb
This line is for Linux, but should do for Windows and OS-X as well. For Linux (and probably OS-X), you can use a script like following, which automatically assigns a timestamp to the file:
adb backup "-apk -obb -shared -all -system" -f "${PHONE:-phone}-`date +%Y%m%d-%H%M%S`.adb`"
Important After doing a backup, verify your data! At my side, sometimes some corruption of the file shows up (and I doubt it is my computer, as I only observe such errors with adb).
Here is a check instruction I use:
set -o pipefail
for a in *.adb;
do
echo "$a";
dd if="$a" bs=24 skip=1 | zlib-flate -uncompress | tar tf - >/dev/null;
echo "ret=$?";
done
It should show ret=0, but it doen't.
If you see inflate: data: invalid code lengths set your archive is corrupted and - very likely - unusable for restore!
If you see tar: Unexpected EOF in archive your backup probably is usable (all backups end this way, I do not know why).
Even if you see just ret=0 there might be undiscovered errors which still prevent a restore.
There is definitively missing an adb verify command, to verify correctness of a backup!
FYI
I post this update, as all other answers were helpful, but not exact to the last detail. (When used with full quotes, a backup was done, but called backup.ab)
Here is my environment:
OS: Ubuntu 16.04
Phone: Android 7.0
ADB: 1.0.32
The full procedure was (just in case somebody stumbles upon this not knowing what is needed):
Zeroth: Install adb (on Ubuntu: sudo apt-get install android-tools-adb)
First: Enable USB debugging mode on the phone.
Second: Attach phone to USB of the computer with an USB data cable (a charge only cable is not enough)
Note that the Ubuntu Phone Manager might show up and ask you for the phone's PIN. You do not need that, close this if it happens.
Third: run adb devices - you should see something like XXXXXXXXXXXX unauthorized
After some time on your phone a message shows up which asks for USB debugging permission
Allow this once. For security reasons, you should not automatically trust the computer, as the fingerprint can be easily faked.
Note that if something is obstructing a single pixel of this confirmation window (like some accessibility feature button) you cannot tap on the OK. First move the obstructing window.
Forth: Now again run adb devices - you should see something like XXXXXXXXXXXX device
If more than one line shows up, you attached more than one phone to the computer. The easy way is to unplug all those you do not want to backup. (The complex way is to set the environment variable ANDROID_SERIAL=XXXXXXXXXXXX.)
Now run adb backup as shown above. Change the file to your needs.
This brings up a window which asks for backup permission.
Do not close the backup window while the backup is taken. When I tried this, the backup stopped and the resulting archive was broken.
You can give a password to encrypt your backup. I do not have any information on how secure the password is. But it is very likely, that you cannot restore the backup taken in case you ever forget this password.
I have no idea on how to restore such a backup to other phones. I even never tried the restore, so I cannot help here, too.
Notes:
adb help shows all possible options to adb backup
Close all open applications on your phone before the backup. I do not know if this is needed, but it certainly cannot hurt.
Leave the phone alone while the backup runs. I do not know if this is needed, but it certainly cannot hurt.
Do not be impatient. Leave the backup plenty of time. At my side I see a progress of about 100 MB/Minute (YMMV). So the backup takes about half an hour for my phone (2.5 GB).
Apparently adb backup does not completely backup everything!
I had a look into the backup (cd X && dd if=../XXXX.adb bs=24 skip=1 | zlib-flate -uncompress | tar xf -) and did not find all installed applications.
What I was able to find was (note that this list is incomplete):
Internal emulated SD-Card: shared/0
External SD-Card: shared/1
Apps: apps/ - many apps (like Google Authenticator) were missing
Calendar: apps/com.android.providers.calendar/db/calendar.db (probably)
What I was not able to find (note that this list is incomplete):
Alarms. (I was probably not able to detect the right app)
Full external SD-card (there is more on this card than what is shown below share/1. For example the apps, which are moved-to-SD.)
Conclusions:
Sometimes adb backup might create corrupt backups, which can go unnoticed. So either check your backup or do frequent backups and pretend to be lucky enough such that not all backups go corrupt.
With adb backup you get a backup of most of your precious data, like camera images and so on. It might be a bit difficult to unpack it, though.
adb backup is not enough to do a complete backup of your phone.
adb backup is not enough to backup your SD-card such, that if it breaks, you are able to replace it by a new one with the contents restored. This is very sad!
PS: The typo "Forth" is not an accidental one.
PPS: zlib-flate can be found in package qpdf on Ubuntu 18.04
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
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)
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
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.
I found this solution :
adb backup -apk -shared -all -f "<path-where-the-backup-will-be-created>.ab"
And to restore :
adb restore "<path-where-the-backup-is>.ab"
I'm unable to access system folder in android without rooted the device. Also wanted to know is it possible to access while booting the android phone?
I think ur asking without doing rooting
so Without rooting you have 2 options:
If the application is debuggable you can use the run-as command in adb shell
adb shell
run-as com.your.packagename
cp /data/data/com.your.pacakagename/
You can use Android's backup function.
adb backup -noapk com.your.packagename
You will now be prompted to 'unlock your device and confirm the backup operation'. It's best NOT to provide a password, otherwise it becomes more difficult to read the data. Just click on 'backup my data'. The resulting 'backup.ab' file on your computer contains all application data in android backup format. Basically it's a compressed tar file. This page explains how you can use OpenSSL's zlib command to uncompress it.
You can use the adb restore backup.db command to restore the backup.
regards maven
Every app can access and read the /system folder on an Android device. It does not have to be rooted for that.
No, you can't.
The user that launchs the application must be root in order to access some folders. If doesn't have permissions to access a directory you cannot access to it. It's a UNIX security measurement, you can't bypass it.