I have been struggling to get TrueNAS Scale installed on my development machine as detailed in this thread. Finally got it over the line, tested SMB shares (Windows only, MacOS test is to come) and have now been struggling with installing the PLEX app.
Google searches (and ChatGPT questions) return a few videos, 'How To’s, walk throughs but nothing really step by step. The main issue I had was the never ending configuration options. It is so long that it even has a floating menu …
- Application name
- Plex Configuration
- User and Group Configuration
- Network Configuration
- Storage Configuration
- Labels Configuration
- Resources Configuration
Here is how I filled it in …
Application name
Umm … gave it a name. The funny thing is that it complains if you have a upper case letter in the name (or hyphen and probably other non alphanumeric characters). It does give you an error message but that error message is WRONG. It says ‘name must start and end with lower case alphanumeric’ - which, to me, implies that ‘plexScale’ is fine. It didn’t like it 
Plex Configuration
Timezone, claim token (a plex thing), image dropdown, local networks, devices, additional environmental variables). I filled in my time zone, killed off some local networks that were NOT my network and just left everything as it was.
I would like to have TrueNAS Scale PLEX on its own, dedicated IP address (instead of using the IP address of the server but that is a research topic for another day).
User and Group Configuration
568 for both. Just left it as is.
Network Configuration
WebUI Port (32400), Host network (CHECKED) and no DNS options.
Storage Configuration
Here is where it got interesting.
This youtube video was very useful. Yes, it was posted over 12 months ago and used a different version of TrueNAS Scale … but he stepped through the set up and discussed what each element meant.
There are 4 path configuations … one each for …
- Data Storage
- Configuration Storage
- Logs Storage
- Transcode Storage
My current TrueNAS Core plex set up has the configuration (metadata) and the media in separate datasets. I thought that ‘Data’ was for the mp4 files, Config was for the metadata, logs for logs and Transcode for Transcoding.
WRONG!
Protopia, in this thread says “‘Plex Data Storage’ is where Plex stores its metadata. Create a new dataset for this, on SSD if you can.”
I also noticed during an earlier Plex app deployment test that a ‘Library’ folder was created under the data storage location. The video above also mentions a ‘Library’ folder (copying it from one location to another as a way of keeping your config).
I selected ‘Host Path’ for each of the above four locations and pointed them to their own folder. I didn’t enable ACL on any of these four locations.
You have the option to add additional storage locations. If you want to organize your plex media at all, then do add locations. I added two … MoviesDVD and TVShowsDVD.
Mount Path: /mnt/MoviesDVD
Host Path: /mnt/CrinkleBag/PlexInfo/MoviesDVD
CrinkleBag is the name of my pool.
Labels Configuration
Standard Stuff.
Resources Configuration
Standard Stuff … but I do spy the GPU config option (but that is for another day).
and add the movies. Repeat for TVShowsDVD and then see if you can watch something.