I’ve noticed that scenario too. I removed my MyBook 1230 last night and it took hours to rebuild content database, but syncing did not work afterwards. I SSH’d into the unit and noticed in the logs my first drive where I attempted to create a safepoint is still be referenced. Maybe a full wipe and restore would fix my problems, but really?
If WD is monitoring if the NAS cannot handle more than one task at a time it is time for a revision. Add better CPU, spend time validating usage use cases, and thoroughly test any new additions .
I’d like to have one of your products connected to perform nightly safepoint backups; be able to eventually serve media content to smart TV/roku; and have a usable sync product that beats cloud based services (e.g. DropBox, Box, Copy, Drive, OneDrive, etc) and competitor products (e.g. QNAP, Synology, etc).
If that cannot be done, I’ll just purchase a QNAP and use this NAS as a last resort.