Backup and restore (TWRP-style)

[GooglyBear]

What do Ubuntu Touch users choose if they want a simple and reliable way to backup and restore their phone, preserving the exact state of the OS so that they can 'roll back' if necessary (eg. bricked phone)?

I haven't really seen a satisfying post about this, so I thought I might as well start the conversation: I'm happy to experiment with different tools and report my findings here as this is a very important feature to me.

[Moem]

@GooglyBear I don't know how TWRP does it.
I would do the following:

• copy the entire home directory to the Downloads directory
• use a cable to transfer that copied home directory to my laptop
• if I need to restore, use the cable again to transfer it to the phone. I've not tried that part, I think.

So I'm not sure yet on how to restore but I do know how to backup. Halfway there?

[Charly]

Hello forum,
before 24.04 noble I always mounted a USB stick in my cell phone and synchronized the folder /home/phablet to the USB stick using:

rsync -rtvP --delete --modify-window=5 --delete /home/phablet/ /media/phablet/STICK/phablet/

or

rsync aP --delete /home/phablet/ /media/STICK/phablet

Unfortunately this doesn't work with 24.04 because rsync has been removed from ubuntu touch.

Best regards
Charly

[gpatel-fr]

@Charly

I have seen one post seeming to say that it was restored in the most bleeding edge version, I can't vouch for it as I use stable, however if you install crackle you can use nix immediately and you can get the nix version of rsync (more up-to-date than the Ubuntu 24.04 version).

https://gitlab.com/tuxecure/crackle-apt/crackle
https://gitlab.com/EricHeintzmann/ubuntu-touch/xiaomi-surya/-/wikis/Install-with-crackle

Once you have crackle running, run 'crackle install rsync' and you are there

[GooglyBear]

I also got some suggestions from the main Telegram group, here is a summary:

(in the case of a broken Ubuntu Touch installation)

• you can run the installer again
  • untick the 'wipe userdata' box
  • you don't need to reinstall any other ROM

This is ideal for my use case as I will actually be setting up software mainly on Libertine, Waydroid and Pocket VMs, which are containerised anyway, while the 'host' OS is for day-to-day essentials such as calling and reading documents.

I am sure taking snapshots/backups of containers is a lot more straightforward than the entire OS (which can be reinstalled to a guaranteed working state anyway): I haven't tried it yet, but with similar tools (Waydroid on Raspberry Pi OS and VirtualBox on MacOS), it was simply a means of copying the files somewhere else and moving them back when needed, so I'm sure it won't be any harder.

I will write again here if I find a way of performing incremental snapshots (a great storage space saver), or for any other useful information on this topic

[Vlad Nirky]

@Charly
rsync is back in the latest 24.04-2.x

[Vlad Nirky]

@Charly

rsync -rtvP --delete --modify-window=5 --delete /home/phablet/ /media/phablet/STICK/phablet/

or

rsync aP --delete /home/phablet/ /media/STICK/phablet

Did this preserve the Waydroid directory and its rights?

[Charly]

@Vlad-Nirky

The first one is for fat32 fs because it has no rights.

If you want copy the rights you need a linux file system like ext4 as target.

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

Thanks for the info of the return of rsync.

Will it be possible to have ext4 on the internal micro SD card in the future?

Greetings
Charly

[GooglyBear]

@Charly Hmm that sounds like a good question for Ubports Core, SD cards still remain immensely helpful for storage - let us know if you happen to find out more about it!

[Charly]

@GooglyBear

Hello,
I'm not really well informed. When I put the micro SD card into my cell phone, only fat32 was possible as a file system. Unfortunately, that's not so good because of the lack of a rights system and the limitation to file sizes of a maximum of 4GB.

I hope ext4 will be possible at some point.

Best regards
Charly

[GooglyBear]

@Charly I see, could this be a device-specific issue? It seems to have been done before here for example: https://xdaforums.com/t/tutorial-howto-convert-your-external-sd-card-from-fat-exfat-to-ext4-3-ways.2480963/

Or did you mean Ubuntu Touch specifically is unable to deal with ext4-formatted SDs?

[Vlad Nirky]

@GooglyBear
Hello.
On my Xiaomi Redmi Note 9 Pro (24.04-2.x), I inserted a 64GB SD card formatted in ext4 by my Fedora 43 desktop.
The card is visible in FileManager+, I was able to add a file to it, and I imagine it would be usable for your rsync...
I run this one as root and it's look good
rsync -avh --size-only --checksum --ignore-times /home/phablet/ /media/phablet/f6466442-e8e6-46bb-b918-89996720569e/phablet-backup/

[Charly]

Hello forum,

I have had the micro SD card in my x23 cell phone for 3 years. I think back then only fat32 was possible. I don't know if anything has changed.

I will try out whether an ext4 formatted memory card is possible.

Best regards
Charly

[Vlad Nirky]

@Charly
Hello.
If I understood correctly, UT formats the SD card in FAT, but on my phone, it was able to use ext4 without any issues. Let me know if it works for you too.

[gpatel-fr]

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

UT formats the SD card in FAT

I'd think that using a command line tool it could be possible to use other formats.

[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.