data
Synchronization
Ways to sync data
There are several options — OpenMediaVault, for instance, has a plugin for rsync, which
handles scheduled synchronization between devices or remote servers.
I personally use the Android app Automate. It's set up to power on the NAS once a week, at night, by sending a magic packet (Wake-on-LAN), then incrementally upload the contents of selected folders from my phone to the NAS.
The advantage of this approach: the NAS doesn't need to run continuously just to back up a
phone — it wakes up, runs the sync, and shuts itself back down on schedule. More on scheduled shutdown and
Wake-on-LAN on the Remote Start page.