Robust sync between Android phone and Linux computer

I already tried quite a few methods to reliably sync data (e.g. backups) between my Android phone and a Linux computer. Most were not good, some were horrible (MTP…). I just tried one that has proven to be the best, by far: installing an SSH server on the phone and then syncing with rsync. I used SimpleSSHD, which does not even need root permissions – and it still worked flawlessly. Sample rsync command:

cd Documents/Backups
rsync -avz --info=progress2 -e 'ssh -p 2222' 192.168.1.5:/storage/emulated/0/ 2018-04-22-phone/

Remarks:

• The IP address needs to be replaced with the one that the SimpleSSHD interface shows
• The password is autogenerated
• The username does not matter
• You can put an authorized_keys  file on the server and log in using your SSH key
• Stopping and resuming the sync process works flawlessly
• The transfer tends to get slow after a while when the screen is off, so either manually turn it on every 20 minutes or let it charge and keep the screen on for the whole process
• Writing to the Android phone seems to not be as easy without root – I set the “login shell” to /sbin/su in the SimpleSSHD settings, and after that it worked fine. An alternative for non-rooted phones might be SSHelper.