Power was cut for a short while at home and when we got Plex up and running again, all of the metadata I had spent months cleaning up etc. had vanished! I have been able to download the database backup from three days previous (which would be fine) but how do you restore from that database? I’ve seen plenty of instructions for people running as plex server from a windows or linux box, but nothing to say how you do it from a WD My Cloud Home? Any pointers?
Nobody ever done this? 
Sorry I can’t help, I’m aggravated as well, and have just started researching the issue. I hate losing all my customized metadata, every time Plex has an issue, and re-doing it. Have you found anything regarding the problem? From what I’ve found, Plex can backup your data, via scheduled tasks, mine is found at; /mnt/HD/HD_a2/Nas_Prog/plex_conf/Plex Media Server/Plug-in Support/Databases. Now it gets a bit hazy, I’m pretty sure everything is done through a command terminal, accessed via SSH, but the exact procedure is unclear, still researching.
I’m assuming no luck in finding an answer? Does nobody at WD or Plex care about WD MyCloud Home users?
For anyone looking for information about this, as of 9/15/2022 there is currently no way to do this without first rooting or jailbreaking the device. This is an issue for all embedded Plex server installations and is not WD’s fault (at least not solely WD’s fault). The Plex interface has a backup function and no restore function… a pretty useless combination without device access.
The Plex software was created based on the assumption that its owner had enough knowledge and access to alter the content of the drive the software is installed upon, but unfortunately most embedded devices do not provide that kind of access out of the box. The actual process is quite simple, stop the PMS server, overwrite the existing DB files with the backup after renaming the files properly, and finally restart the PMS server. The databases themselves are SQLite3 database files.
The only good solution for this on MyCloud would be through the creation of an app for the platform that handled the process on behalf of the user, but such an app does not exist and there is little documentation on how to build one if a developer was inclined to do so. As a result, unfortunately, the MyCloud is not really the best host for running Plex.
