Hopefully, someone else has tried this and knows what I’ve done wrong?
I have Docker installed on OMV, and thought it’d be nice to containerise my services like Plex; this is the one i started with 
Unfortunately, I’m running low on OS space, so thought I’d move the Plex libraries to my Data Drive using the /config option. Although, my libraries get scanned and catalogued, and photos/music play, no video files will play. I assumed it was transcoding not working as there are no errors plex just sits there spinning with no movie playing? I tried to set the /transcode option back to the OS drive instead, in fact read to move it to RAM to /tmp, but this is still not working. I can see the transcode session folder getting created, but no files generated there and still no video files playing 
The only thing I can see in the plex logs is:
Apr 18, 2018 08:26:00.238 [0x7f84b53fe700] DEBUG - Completed: [xxx.xxx.xxx.xxx:58106] 404
GET /video/:/transcode/universal/dash/7msb1ixpbdj7tbdf801568mc/0/0.m4s (10 live) TLS GZIP 0ms 452 bytes (pipelined: 3)
A
Any suggestions please to get this working? The only thing I’ve read was it might be due to “noexec” option is on the Data Drive and I ran into this problem when trying to move Docker to the Data Drive, I got “exec permission denied” errors trying to run containers; is it the same problem with the Plex libraries?