How can I backup and restore Cyanogenmod 12.1 rom installed on my Samsung Galaxy 2 i9100?
I found a link to a signed stock kernel providing TWRP v2.8.7.0 on xda Forum : [ROM][I9100][5.1.1][OFFICIAL] CyanogenMod 12.1 Nightly Builds

It can be flashed with the Cynogen Recovery.

https://www.androidfilehost.com/?fid=24052804347787517