Re:Ask HN: How to maintain an identical "hot standby" Androi...
by threaderr on Sunday November 05, 2023 @09:19PM
(#38158038)
I agree with the posts above, though I will add that sandboxing apps like Insular work around some apps misbehaving when rooted where things like even Magisk hide fall short. I would unlock the bootloader, write TWRP to recovery and go that route somehow (rsync or something? I'm envisioning maybe plugging your phones to a usb ethernet adapter here, I don't know if it's even possible to WiFi or network from TWRP though so .tar.xz?).
Devices are a bit more complicated then they were just a few years ago, a cryptographic salt is stored somewhere, and the trim area (TA) plays a role, so you would run into trouble simply writing (dd) the /data partition to your second phone, but all you really need to do is keep the /data partition and /sdcard synced. Surely a script leveraging the features of TWRP seems like it should just work though?
Cheers, lovely question! - threader
With root, some app to do backups and restores of system/app data (which is why you'd need root), + syncthing, you can probably get 99% of the way there.
Buuuut... You now have the problems of root, which means a lot of apps won't work out of the box, you'll have to do some per app config to hide root/unlocked bootloader from them, and that's only getting harder.
So tl;dr don't use smart features, and only deal with syncing calls/sms/photos. The rest you do via the browser.