Full backup of Android apps + data using adb

README.md

Back Up Android Apps and Data in Modern Times (2024)

What happens to your apps if your phone breaks? Phones have become an essential part in our daily interactions with banks, social networks, entertainment, and what not. Losing or breaking a phone has never been more nervewrecking. Especially with apps that use local only storage with limited or no means of backup. Backing up data on Android is becoming harder, even for advanced users.

A decade ago, there were still viable options available for power users. Apps like Titanium Backup come to mind. But Android is being locked down tighter every year, because of financial regulations and trusted computing requirements. This mindset of turning phones into walled gardens where even a power user shall have no access is trickling down to forks such as LineageOS as well.

Modern versions of LineageOS, 18.1 as of the moment of writing, do no longer provide a practical way for applications to gain root. Backup applications such as Titanium Backup no longer work. There are much more intrusive methods such as Magisk and boot image patching available in order to get these backup apps to work, but this is far from ideal and may come with considerable risk.

There are backup options available today in Android distributions, but many apps now downright refuse access to any of their data. Without judging, all of this is done in the name of security, regulations and preventing malicious abuse. But as a result, these backup methods as well as the apk backup and apk restore commands no longer provide a proper full way of backing up app data. They are next to useless for backup purposes.

In the meantime, a lot of seemingly shady backup apps have sprung up. Some of them need root access and consist of odd scripts. In short, none of them can be trusted.

So why not back things up manually? This quick 'n dirty guide to get you started!

1. Method

Currently, the /data partition is still accessible through a adb shell with root privileges, which can be gained with adb root by only changing some non-intrusive settings on the phone. This means that app APKs and data can in fact be backed up and restored as before, without any external tools, by using a adb-capable host machine.

Something can be said about the security implications of supplying root to apps on the phone.. that's all understandable, as long as they don't take root on our phone away from adb!

Some things to keep in mind:

• Some apps may not respond well to their data being restored on a different machine, such as Signal. These apps will typically crash immediately when started. For example, some apps may encrypt their data using a keychain on the phone which makes it very difficult to restore things.
• Use adb logcat to debug any issues with apps.

2. Apps

2.1. Backup

Download all app APKs from phone to current directory.

Bash:

for APP in $(adb shell pm list packages -3 -f)
do
  adb pull $( echo ${APP} | sed "s/^package://" | sed "s/base.apk=/base.apk /").apk
done

Powershell:

foreach ($APP in $(adb shell pm list packages -f -3)) {Invoke-Expression $($APP.replace('package:','adb pull ').replace('base.apk=','base.apk ')+'.apk')}

2.2. Restore

Upload all APKs in current directory to phone.

Bash:

for APP in *.apk
do
  adb install ${APP}
done

Batch:

for /f %f in ('dir /b .') do adb install %f

3. App data

Make sure adb has root access.

Host:

adb root

3.1. Backup

Upload backup_data.sh bash script.

Host:

adb push backup_data.sh /data/data/ && adb shell chmod 755 /data/data/backup_data.sh

List apps

Host

adb shell ls /data/data/

Backup

Assuming /data/data/_backup as location on phone for tarballs, though this can be changed.

Backup specific app:

Host

adb shell bash /data/data/backup_data.sh /data/data/_backup com.google.android.apps.authenticator2

Pull backups

Assuming /data/data/_backup as location on phone for tarballs, though this can be changed.

Host

adb pull /data/data/_backup

3.2. Restore

Upload restore_data.sh bash script.

Host:

adb push restore_data.sh /data/data/ && adb shell chmod 755 /data/data/restore_data.sh

Push backups

Host

adb push _backup /data/data/

Restore

Restore specific app:

Host

adb shell bash /data/data/restore_data.sh /data/data/_backup com.google.android.apps.authenticator2

Restore all apps from /data/data/_backup:

Host:

adb shell cd /data/data/_backup && for f in *.tar.bz2; do bash /data/data/restore_data.sh /data/data/_backup ${f%.data.tar.bz2}; done;

Cleanup

Host

rm -rf /data/data/_backup

backup_data.sh

#!/bin/bash
dst=$1
name=$2
if [ -n "$name" ]
then
  if [ -n "$dst" ]
  then
    echo Backing up app data: $name
    cd /data/data
    mkdir -p $dst
    tar jcf $dst/$name.data.tar.bz2 $name
  fi
fi

restore_data.sh

#!/bin/bash
dst=$1
name=$2
if [ -n "$name" ]
then
  if [ -n "$dst" ]
  then
    uid=$(cat /data/system/packages.xml | grep -i '<package' | grep -i $name | sed -n 's/.*userId=\"\(.*\)\".*/\1/p')
    if [ -n "$uid" ]
    then
  	  echo Restoring app data: $name, uid: $uid
  	  tar jxvf $dst/$name.data.tar.bz2 -C /data/data/
      chown -R $uid:$uid /data/data/$name
      restorecon -R /data/data/$name
    else
      echo ERROR: Could not find uid for application $name
    fi
  fi
fi