In the process of building a new box for out plex server. Been using Win10 (upgraded from 7) with no real issues. Thinking about moving over to Ubuntu 16.04 instead of Windows10. This may not be the right place to ask whether Ubuntu 16.04 is supported and pros/cons of Linux derivatives vs. Windows but would appreciate any input.
Currently we have ~350 movies sitting on an external USB HDD (with another as a backup). Server is hard connected to the router and two of our children do access remotely to stream movies.
Appreciate any links to articles or discussions on this topic.
I’ve been running Plex on Linux for 3+ years, and it’s great. I’m currently using Linux Mint 17.1, which is based on Ubuntu 14.04, so I can’t speak to Ub16.04, but I doubt you’ll have significant problems.
You’ll likely get more knowledgeable discussion if you post your question in the PMS/Linux forum.
I’m running PMS on Ubuntu Server 16.04 (running in a vm on Hyper-V). It is definitely supported.
As long as you properly mount your external hard drive so that the plex user can have read permissions to it you’ll be fine. I like the fact that it runs as a service on Linux, where as on windows you have to do extra configuration to set that up using a third party wrapper. A con is that you should be at least decently well versed in Linux or you’ll likely run into issues with permissions, there are tons of threads here about that very issue. Another con could be that there isn’t an auto update built in and there aren’t any repositories (official at least) currently, so you need to download the deb and install it manually. There are scripts on the forum that people have made to do this update however as well.
Really, there’s not a ton of reason to go one way or the other besides choice, pick what you are comfortable with and you’ll be fine. 
Further to the other posts, I’d highly recommend connecting your network shares using NFS instead of Samba. NFS uses less CPU power, and it disgustingly fast. It’s not difficult to setup either.
I have my NAS mount as an NFS network drive every time the server reboots with a little addition to the fstab.
On a Gigabit network, it’s more than capable of maxing out the connection with minimal overhead
Can’t speak to 16.04, but I have it on 14.04 (never go bleeding edge with systems your wife uses. ever.), and the drive mounting of the USB drive was the hardest part…the rest proved quite simple, and plays very nicely with the rokus and androids and such in the house.
I’m using 16.04 on an Headless Intel NUC. Virtually bulletproof, just works.
I have my NAS’s mounted via Samba and they work fine, no problems. I didn’t try NFS.
Get familiar with command line working and SSH
There are a lot of information pages out there for setting up Unbuntu, I had a few head scratching moments. But after a little searching the information was there.
Try this link:-
thisisforsomething.com/2016/08/31/guide-to-the-ultimate-plex-server/
