Backup and restore (TWRP-style)

[Vlad Nirky]

@gpatel-fr
Yes, I was thinking to the SD app present in Lomiri panel.

[gpatel-fr]

@Vlad-Nirky

looking at the 'ciborium' code, it is hardcoding only exfat at one point, when checking on dynamic insertion of a sdcard. I will not be able to do any tests on that since my phone can't accept a new sdcard without removing the battery.

[GooglyBear]

@Moem Thanks for your input, backing up your home directory is definitely a great idea and is what people normally opt for.

Below I'll try and summarise what I've learnt for solving my problem, which might help people facing a similar problem.

Please remember I have not tried restoring yet to see if every single thing on the list was backed up, the one thing that's certain is if you have files in the home directory and you back up that, those are safe (you can always check they successfully made it to your computer by browsing inside the folder).

Backing up your home directory

1. Connect phone to computer.
2. Make sure the adb command is working (run adb devices to see if there's any output etc.).
3. Run adb pull /home.

You should receive some output about whether all your files made it to your computer, and obviously you can check for yourself by browsing them on your PC.

Why should I backup userdata instead of just home?

If you want to take it a step further, I'd recomment backing up the entire userdata folder, which also contains the home folder mentioned previously: as far as I've been able to gather just by asking other users on UBPorts' Telegram servers, this includes the items on the list below.

Things inside userdata which are useful to back up

• the settings you changed in the settings app
• your fingerprints for unlocking your phone
• the apps currently installed on your device
• the apps' data: for example, all the apps and everything else needed to run your Waydroid container exactly in the state it is in now
• packages installed via nix and snap

Backing up userdata

Do the same but run adb pull /userdata.
Basically if you ever lose your userdata you just need to replace your current /userdata folder on your phone with the previous backup of /userdata on your computer.

While I would probably simply run something like adb shell 'rm -rf /userdata && mkdir -p /userdata' && adb push /path/to/userdata /userdata for restore, do not run it unless you know what you're doing, I have not verified this to be working and need to check with people more knowledgeable than me on UT to confirm/fix.

This is the best I have for now, I'll update / add to this if I come across anything better

[Vlad Nirky]

@GooglyBear
With this procedure, are Waydroid's specific directory rights preserved?

[GooglyBear]

@Vlad-Nirky The truth is I have no idea, only way is to test it I guess. I also assume I'll have to run adb root first to download all files.

The adb user documentation (https://android.googlesource.com/platform/packages/modules/adb/+/refs/heads/main/docs/user/adb.1.md) doesn't seem to be of much use in answering this question.

[GooglyBear]

@Charly said in Backup and restore (TWRP-style):

If you copy to an ext4 usb stick and use rsync with sudo, all different rights should be applied correctly.

This might help I suppose, and there's probably a way to configure rsync to work via cable. We'll see...

[Vlad Nirky]

@GooglyBear
I'll try...
Hum. No, the pull don't have access to waydroid data folder.

adb pull /home/phablet/.local/share/waydroid
/home/phablet/.local/share/waydroid/: 0 files pulled, 0 skipped.

[GooglyBear]

@Vlad-Nirky Did you run adb root beforehand?

[Vlad Nirky]

@GooglyBear
No, only the commands mentioned above.
Let's try again.
It seems that adb root is disabled by default.
You need to add a module to be able to use it.
Is that correct?

[GooglyBear]

@Vlad-Nirky Hmm, not sure. Running adb root for me gives error message adb: unable to connect for root: closed, but I can use sudo inside adb shell: using that would probably let me get a step closer, by allowing me to copy data to an SD card for instance. The problem is my computer isn't an adb client so I can't just use my phone as a host and run adb root on it.

Going back to the module installation, I should definitely look into that (or whatever procedure I need to enable adb root), as it sounds better than the whole hassle of the SD card (which funnily enough is one of TWRP's limitations).

[UPDATE]

I've been told by an admin of UT's Telegram group that adb root simply hasn't been added to UT. This shouldn't be a problem, as utilities like rsync and scp, which are meant to work over a network, can be set up to work over for example USB (or maybe even Ethernet, don't know which would be faster or in what scenario).

I may test backing up and restoring a Waydroid container with SD card, SSD and PC (using sudo on UT so that I have the priviledges to save all kinds of rights).

I've been told by the same admin this works: therefore, all that's left is finding the right command for the job, so that it restores a Waydroid container to a working state (although this procdeure should be applicable to any app or user data or configuration).