Johnny Matthews | Rsync files to Android

Rsync is a super handy utility that makes synchronizing files between two systems incredibly simple. Unfortunately, Android doesn't allow users to use this utility straight out of the box. This post discusses why the restrictions exist and how to get around them using ADB-sync. This was written on 17th of July 2020.

This restriction has something to do with how Android is mounted when connected to a computer over USB. It’s not actually a full file system but uses the media transfer protocol (MTP). MTP is ok but can cause issues when transferring a large amount of data. For instance, I want to copy my entire music library from my laptop to my phone. It’s about 30GB, and MTP can sometimes crash about halfway through.

Annoyingly, to get Rsync to run natively on your Android, you need to root the phone. There are pros and cons to rooting a phone, but one major con is that it’s a long and laborious task that I can’t be bothered to do.

Enter ADB Sync! Google has thrown a package together that essentially acts as Rsync using the Android Debug Bridge (ADB) tool. It’s super simple to use and does the job.

Install ADB Sync

  1. Install ADB on your computer:

    sudo apt install android-tools-adb -y

  2. Check ADB is installed properly:

    adb --version

> Android Debug Bridge version 1.0.39
> Version 1:8.1.0+r23-5ubuntu2
> Installed as /usr/lib/android-sdk/platform-tools/adb

  3. Grab the ADB Sync package from GitHub and move it somewhere handy:

    git clone https://github.com/google/adb-sync
cd adb-sync
sudo cp adb-sync /usr/local/bin/

  4. Check that ADB Sync is installed properly:

    adb-sync

> usage: adb-sync [-h] [-e COMMAND] [--device] [--emulator] [-s DEVICE] [-H HOST] [-P PORT] [-R] [-2] [-t] [-d] [-f] [-n] [-L] [--dry-run] SRC [SRC ...] DST
> adb-sync: error: the following arguments are required: SRC, DST

  5. Now you can use adb-sync to sync files between your computer and your phone.

Sync files

To synchronize your music files from ~/Music to your device:

adb-sync ~/Music /sdcard

To synchronize your music files from ~/Music to your device, deleting files you removed from your PC:

adb-sync --delete ~/Music /sdcard

To copy all downloads from your device to your PC:

adb-sync --reverse /sdcard/Download/ ~/Downloads

That’s about it! Pretty simple stuff.