Is wiping data necessary when switching OSes?

[matthijs]

@paulakreuzer

PS: I just tested by mistake. I switched from FP OS to MM beta, then to FP Open and back to FP OS and haven’t lost any data or apps.

I suspect you did this using adb, fastboot or recovery to update just the system partitions, not the data partition? AFAIU the OTA-updater/switcher clears the data partition when switching, to prevent potential issues with apps getting confused by missing or extra stuff in the data partition.

[TobiasF]

@matthijs

AFAIU the OTA-updater/switcher clears the data partition when switching

According to the update support article, it seems that the data partition will not be cleared.

[paulakreuzer]

@matthijs

AFAIU the OTA-_updater/_switcher clears the data partition

@tofra

According to the update support article, it seems that the data partition will not be cleared [when updating from FP OS (Android 5) to FP OS (Android 6)].

Italic was added/edited by me. Now your two statements don’t contradict each other anymore.

@matthijs yes, I forgot to mention that I used TWRP and of course you are right: that’s why data was not deleted.

I don’t think it makes sense for the FP Open to FP OS switcher to wipe data. The other way round it makes sense to get rid of all G%§$e stuff (they infect all partitions). Switching from Open OS without wiping the worst thing that can happen is you have to uninstall apps afterwords that don’t work anymore (because they need root, Xposed framework or other modifications).

[matthijs]

@paulakreuzer

Switching from Open OS without wiping the worst thing that can happen is you have to uninstall apps afterwords that don’t work anymore (because they need root, Xposed framework or other modifications).

I can also imagine that some Google apps expect things to exist on the data partition (e.g. created by the first boot or on-boarding process on first boot) that won’t exist after such a switch, and may break. No clue if that actually happens, but this morning one of the developers did mention that some apps can end up crashing when the data partition is not cleared (no further details mentioned).

I wonder if this wipe-data-on-switch discussion should be split off in a separate topic? I don’t think I have permission to do that, though.

[therob]

Is it a fact, that we need to make a factory reset at all?
(which means, that we loose all stored data and NEED to do a backup, right?)

Or is there any strategy to avoid a factory reset?

[paulakreuzer]

There is no need. You can even switch from Open OS Lollipop to FP OS Marshmallow via TWRP/fastboot/adb without loosing anything. But some things may not work afterwards or even cause troubles.

[spaetz]

I needed to reinstall a few apps after upgrading as they simply started to crash after the upgrade. Reinstallation of the apps worked fine though.