@Flohack Regarding the user-data folder, it took at least 30-35 minutes to backup 12Go (including compression) over usb2.0, and nearly the same (a little faster) to restore (arround 20 minutes).
The system-data folder was smaller then it take less than 5 minutes to backup (and 3 more to restore).
I was thinking about doing it on the SD at the beginning but as my data partition was about 54Go, I was scared that my 32Go SD card wasn't sufficient (as I already had a lot of things on my SD like all the pictures taken by the camera, they are very big on te Pro5 because of the sensor quality).
And one other thing was that my sdcard wasn't mounted on recovery, I think that the recovery-turbo.img miss a lot of features.
For the phone where the system-data and user-data are correctly mounted on the /data folder in recovery, this script can work well if you remove the line "adb shell mount /dev/block/sda44 /data"
But if you want to do that locally on the SD card, if it is mounted, you can do that on the recovery nearly the same way, don't forget to use tar as it will take care of the symlinks (not to ignore them, it will save them too).
It will be very perfect if that can be integrated to the installer !
@dobey Hi, at the beginning i was thinking about coding everything into ofono then push notification to the dialer-app. In the mean time, as we have to handle imaps I though that it was better to do it in a separate process, just in case that the app crash because of a connection lost. That's why I was thinking about pushing notifications from this other process to the dialer app. I was not aware about telephony-service (or it come out of my mind while thinking about the project). Actually I modified ofono for pushing VVMMessage signal over dbus to my process, the I handle the imap and a separate sqlite database that store the list of messages and the imap configuration, I'm able to download the messages locally. I have to modify the dialer-app, it will have to read the DB and to require the message download or deletion over DBUS through my process. I think this way is less intrusive for the overall telephony apps. As far as I can read over the net, it seem that they did the same way on Android.
A last but important point, my secure imap connection is made by using curl, I'm a little scared because I don't see the libcurl natively on the file system, I hope that we could add it ! otherwise, I will have to use an other library.