I am quite new to Android and I would like to be able to make a complete backup of an Android smartphone storage so that I can restore everything in case I mess it up or it breaks. My plan is to buy another phone of exactly the same model and restore my image to it so that I get exactly the same system back as the old one was at the time of the backup.

I have some experience doing this with a laptop. In this case I boot the laptop using an external USB stick with a live Linux distribution (let's say the USB stick is /dev/sdb after boot), attach an external drive (seen as /dev/sdc) that is larger than my laptop's internal disk (/dev/sda). From the live system I then do something like:

# mount /dev/sdc1 /mnt
# dd if=/dev/sda of=/mnt/sda.img
# umount /mnt
# reboot

The procedure for restoring the image is similar.

I have found some guides and questions on how to do this on Android but most of them show how to backup user files or individual partitions, which is not what I want.

I illustrate my questions with reference to this guide (from which I would prefer the adb + dd method, because it does not require to install additional software).

Question 1 The guide says that I should root the device: why is this needed?

Question 2 The guide shows how to make images of individual partitions but I would like to make an image of the whole system device with something like

dd if=/dev/mtd of=...

Would this work at all? Since I have to boot the device in order to connect to it with adb, will one or more partitions be mounted? Of course, I do not want this: all filesystems should be unmounted while I perform the backup.

Question 3 Is it possible to transfer the image over to my laptop directly, without writing it to an SD-card?

  • That's three questions. On StackExchange you should ask one question per post.
    – Chenmunka
    May 22, 2021 at 18:40
  • 1
    Q1: You need root access because Android is designed this way. Users don't have access to everything. It is the same on Linux ( here you need root or a sucker user + sudo), the only difference on Android is that on regular Android devices it is not planned that anybody gets r lot access.
    – Robert
    May 22, 2021 at 18:43
  • 2
    "That's three questions. On StackExchange you should ask one question per post.": My question can be summarised as follows: How do I do a bitwise image of the smartphone storage and copy it to my laptop without modifying it and losing the warranty? (As far as I know, if I root the phone or unlock the bootloader, the warranty will be invalid and all user data will be wiped.)
    – Giorgio
    May 22, 2021 at 20:14
  • Does this answer your question? Can I flash Android on device with overwritten mmcblk0?
    – alecxs
    Mar 12, 2022 at 17:25


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