The DS 218+ makes a fine Plex Media Server as long as you are aware of its limitations.
Read these two documents:
Installation and Setup of Plex Media Server on Synology
They will save you time, trouble, and headaches.
For example, do not use the /video shared folder. It is reserved for Synology applications such as Video Station. Using it for Plex will lead to wasted time, trouble, and headaches.
You also need to be aware of the limitations of the DS 218+. Primarily, without a Plex Pass, it will struggle to transcode video. This is noted in the NAS Comparability List (spreadsheet linked in document). If your clients cannot direct play or direct stream the video, you can expect buffering and stuttering as the NAS CPU struggles to transcode in real time.
You can view playback status via the Plex Dashboard.
Make sure you follow Plex guidelines for media organization and naming. This is especially important with TV shows. Plex may import & match your media otherwise, but in reality you’re just getting lucky. Spending the time up front to correctly organize & name your media will save you time and headaches down the road.
