I have an Android phone with 64GB of storage and I take a lot of pictures and video (parent young kids). Whenever my phone storage space starts getting full, I transfer the files to my NAS server (also backup on Google Photos). Rather than manually transferring the files to my NAS, I figure I give ST a try. I setup Syncthing on my Android phone and selected my Camera folder. It was set to “Send Only”. I then shared the folder to my desktop computer and starting syncing to my NAS. ST then started deleting all of my photos and videos that were not on my phone! Luckily, I have another backup of this data on an external drive. I disabled ST and restored my data to the NAS.
I did not expect ST to delete data on my NAS, since the Android folder share was setup as “Send Only”. Is it possible to use ST as a backup solution in my situation?
Syncthing is not backup software as you’ve already discovered.
Syncthing would not delete anything if its set to send only, perhaps some other process did that. You should open the web ui on the phone and verify the folder is actually visible as send only (should be a line in the box representing the folder). Perhaps there is a bug between the android ui and the syncthing application.
I can confirm the case that content in peer 1 “Send only” is retained, here it means “phone storage space”.
The other peer 2 is left at default, ie “send & receive” or “receive only”. You will then be asked to confirm “overwrite changes”. If the comparison is started via this label, peer 1 is always mapped to peer 2.
If you want to use syncthing as backup software you need to enable " ignore delete " on your NAS. You can find this option in the web UI > Actions > Advanced > Your Backup folder.
Another small tip… if you want to try a new backup software just make some test with a small folder and just a bunch of dummy files before to make some mess !!!