A long time ago, when I tried something like that, I was stymied because the SSH server did not have permissions to write to any directory which the document readers etc. could see.
Is this sort of thing still a problem? How did you get around it?
Is this sort of thing still a problem? How did you get around it?
Since Android 8 I've lost write access to general locations in the sd-card but I still have read access, as well as read+write on the internal storage.
It has an ssh server which can be nice if you want to edit some files on the phone remotely but that's not needed for rsync. I have a shortcut on the home screen which triggers a script that runs an rsync command for photos and other stuff I want to backup. Also use it to reverse-sync a folder from my NAS, want to send a file to the phone? But the file in that folder and run the script.
I don't see anything in that link that says that sdcard (outside private folder) is read-only.
The way I read "Each app has a private folder on the external SD card, and interchange between them needs to use a special API not yet available in Termux." is that I can't read another applications private folder, but I'm not trying to - I just want (write+delete) access to the publicly accessible parts of the sdcard (lots of other applications do this, and termux did in Android 7).
My phone isn't rooted. Everything in /storage/emulated/0 backs up without issue. Obviously not a full system backup, but all my data none the less.
With regards to write permission, I've only ever issued any writes to my image folders to prune photos or screenshots older than xx days that have already been backed up. On that note, freeing up 20GB of space instantly with a single command is incredibly satisfying (compared to the MTP hell alternative).
I use this method to rsync to btrfs snapshots (+ raw copies of non-filesystem partitions) to make daily incremental backups of the entire phone. (Restoring said backups is a bit more involved, but I verified it's doable.)