Backup testing

[kmsgli]

I have tried a few different backup solutions i found on the forums here that do not work. I am in a good position to test this as i have two pixel 3a's one for testing (cracked screen) and one for my daily driver. The few scripts I found to work are just home folder copiers which is not really a backup solution. The adb pull /data/system-data /data/system-userdata does not work from recovery. I also tried TWRP which takes the backup but wont restore on the other device.

Anyone have a working solution or something I can test since i have two phones.

[Alaraajavamma]

I use to struggle with same problem but then I find this somewhere in the forum (sorry I don't remember who is the original advisor)

This solution works on OPO and Volla. I also tried to migrate my settings from OPO to Volla with this but that did not work - OPO -> OPO or Volla -> Volla works fine

Source device

After connecting source device on PC commands in terminal as follows:
Reboot phone into recovery: adb reboot recovery
Acquire root: adb root
Activate shell: adb shell (command prompt will change to # sign)
Backup system-data (this will also create log files, that can be examined for possible errors) :
tar -czpv -f /system-data.tgz /data/system-data/ >/system-data.out 2>/system-data.err
tar -czpv -f /user-data.tgz /data/user-data/ --exclude='data/user-data/phablet/.cache' >/user-data.out 2>/user-data.err
logout from shell to your terminal
Ctrl+D

go to directory where backup data are to be stored in PC
adb pull /system-data.tgz
adb pull /user-data.tgz

Destination device

Reboot phone into recovery: adb reboot recovery
go to directory where backup data are to be stored in PC
adb push ./system-data.tgz /
adb push ./user-data.tgz /

Activate shell:
adb shell
tar -xzv -f /system-data.tgz
tar -xzv -f /user-data.tgz

[kmsgli]

@alaraajavamma

that is similar to this post
https://forums.ubports.com/topic/1498/backup-complete-device/9

@Bastos in post number 9 says adb pull /data/system-data but my phone has nothing in that folder nothing to backup data is an empty folder?

[Alaraajavamma]

@kmsgli I am not expert on this but I have tried multiply backup methods.
Only one what I managed to get working 10/10 is the one what I wrote on my message.
As far as I can tell with my experience: if you use that method you can actually restore everything (including sms, phone calls etc.) as long as you try to restore it to "same device" = not excatly the same one but OPO -> Volla did not work but OPO -> OPO working.

Bastos methot is mostly the same but I have tried it also and it did not work.
As said I am not an expert but if you follow my message step by step you might get it working (that is what I did - I just copy&pasted someones idea )

[Emphrath]

@alaraajavamma Afaik someone is working on making a backup solution working from the installer