LineageOS 14 (Nougat)

I decided to try LineageOS 14.1 (Android Nougat 7.1) on my aging Galaxy S3. Since acquiring a used S3 about two years ago, I had been running CyanogenMod 12 (Android Lollipop). I wanted security and feature updates.

Tools currently used:

• TWRP recovery (TeamWin Recovery Project). This is a handy way to make backups of operating systems, applications and application data. It does not backup SDCard contents. It can use USB On-The-Go (OTG) and can generally read encrypted data volumes, using the same unlock as regular boot.
• TitaniumBackup. This product is an excellent way to make backups of current applications with data and is a virtual requirement to restore a phone to its prior usability after a major OS upgrade.
• I keep a stock operating system copy for PRL updates. I backup the live OS, restore this, perform a PRL update, then restore the live OS.

To complete the upgrade, I performed a backup with TitaniumBackup, a separate OS backup with TWRP, then copied all that to another machine for safekeeping.

Then I wiped /data, /system, and installed LineageOS 14 and Google Apps using TWRP. After booting and restoring connection to my Google account, I installed TitaniumBackup and restored my applications with data. At that point, I did have to rebuild my home screen and tweak options with Nougat to reduce battery consumption and data usage.

Finally I chose to encrypt. I'd been putting that off for some time, but decided to take the plunge. It worked fine. It encrypts only the internal /data, since I chose to keep the SDCard as a separate volume. It does require an extra step at boot, but is otherwise unnoticeable. I detect no degradation of performance and my S3 is still great, five years after its introduction and running a current operating system that is nine major releases past what shipped with it (counting the three separate Jelly Bean and two Lollipop released), much better than the manufacturer and original carrier would have offered.