LinuxQuestions.org - Moving Docker Path

I'm really trying to learn Docker, even though I'm a linux novice. My biggest issue, is that my OS drive is limited and so I've been trying to move it elsewhere.

I tried moving the Docker path (/var/lib/docker) but then I got exec permission problems (probably becuase my data drive has noexec option on it?

I haven't tried changing that yet, as it's probably worth leaving that option on the data drive for security reasons?

Therefore, I pulled a Plex image, and created a container with the /config set to my data drive. It was all working, except for playing video files (sort of the main purpose of plex)...which I thought may have been an issue with transcoding. So I tried moving the /transcode folder to another location and even to /tmp, but this isn't working either. I can see in /tmp the transcode session folders with docker permissions, but the video files still aren't playing. I looked in the log, but just saw these:

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

Could this still be because I have the noexec option on the data drive where the plex volume is now being stored? I'm still tryign to understand how this all works.

I'm not sure whether I should give up and just get a bigger OS drive and figure out how to image it instead and just leave everything to default settings in future?

Any advice would be appreciated to help me along the way :)