Make sure I have the install files with which I installed the old OS (+ Open GApps in my case).
Use MyPhoneExplorer to “Multi-Sync” everything there is to sync … complete Internal Storage, contacts, messages, photos etc. … to my PC to be on the safe side with a data backup.
Make a full system backup in TWRP and copy that to my PC.
Then I can wipe and format and test all I like, and if I want to have the old system back …
Wipe everything in TWRP.
(In case encryption is gone … disassemble new camera modules, install the old OS and immediately encrypt the phone again, encrypts very fast this way because there’s almost nothing in Internal Storage … reassemble new camera modules.)
Restore the TWRP system backup.
(In case the phone doesn’t want to boot afterwards, install the old OS again over the restored backup, this got it to boot reliably for me.)
Boot the old OS and use MyPhoneExplorer to “Multi-Sync” all my data back to the phone
And voilà … back on the old system as if nothing happened .
Edit for a slight correction: My ringtones aren’t back after the restore.
The system backup restores the ringtone settings, but as my custom ringtone files don’t come back until Internal Storage gets restored, the OS cleverly reverts to default sounds.
I’m on MacOS and I’m doing backups of apps/data/some system prefs (user dictionary) via Titanium Backup (oandbackup has failed to restore data for me in the past). I then do system backups with TRWP and copy the whole thing (aka the virtual „sdcard“) to my Mac with adb (which can be installed via Homebrew). I use Androids pretty bad Android File Transfer app to copy audiobooks to the device sometimes
Showed the Android robot for a moment, then rebooted and in the process somewhen showed the Android robot again and encrypted the phone.
So far, so good .
But … @z3ntu TWRP 3.2.2-0 can’t handle this encryption yet?
It prompts for the password (even if the setting in LineageOS 15.1 was “None”), but fails to decrypt. Even if I set a password (not a PIN like I used to) for the encryption in LineageOS 15.1 and I’m trying the correct password in TWRP.
And … @chrmhoffmann While a start pattern works, I noticed that regardless of whether I set a start PIN or a start password the phone then prompts me for a PIN and I can only enter numbers. Which isn’t intended when having set a password, I guess?
As I was coming from Ubuntu Touch who have their own recovery, I used the recovery image from the first post to install today’s image plus opengapps pico via sideload. Worked perfectly. First time wizard is completed, phone is up and running. Thanks
Some more problems: I wanted to download the fdroid app from their webpage in Firefox. After tapping the download button, I see “Starting download…” in the Firefox status bar at the bottom. But then nothing happens.
For the moment I installed it via adb install /path/to/FDroid.apk from my PC.
Then I wanted to install the fdroid priviledge extensions. Installing the OTA package puts the actual install ZIP file in /data/user/0/org.fdroid.fdroid/ota which then needs to be installed from recovery. But that failed with the lineage recovery
navigating to the above folder was impossible; if the folder/file list is too long, you can scroll down but when you tap the desired folder, it actually evaluated the tap as if you hadn’t scrolled at all (tapping “user” actually opened a folder starting with “a”)
after copying the ZIP file to the SD card I could select it for install but then the installation failed