Thinking of switching to windows or truenas for a new jellyfin build

[TheDreadPirate]

appreciate the help and replies, it helps me a ton.
so just to be clear, I put my system together and install ubuntu desktop onto a little ssd (128 or 256gb is ok?)
create a raid array in ubuntu with all my drives in it..
- question, will it recognize sas drives and a LSI controller flashed to IT mode? I'm assuming it should
also I'm running a 10gb lan using mellanox x3 nics with sfp to cat 6 adapters, to a unifi aggregation switch connected to a bunch of other unifi gear (my other 2 servers, main desktop and torrent box are also on that aggregation switch) I can saturate that 10g from nas to desktop, but not in reverse, mech drives too slow)
I guess I'll have to figure out what to do with those, hopefully ubuntu will recognize them

Any hardware OMV can run Ubuntu can run.

continuing on, docker is already installed with ubuntu, I can just install portainer from there, create directories, populate them with media, do the pull for jellyfin and point it to my directories get it all configured and then just leave it alone for months on end? 

that's what I'm looking for, OMV spazzes out every now and then and makes me reboot the whole array, some kind of memory leak or something. I don't like restarting my array if I can help it, the server(s) are behind a firewall and not connected to the internet, just the lan, so not too too worried about updates, just want long term stability wtih a minimum of reboots

Linux, in general, doesn't force reboots for updates like Windows does.  I restart every 2-3 weeks for kernel updates, but my jellyfin is Internet accessible so security is a concern.

sorry if it's a lot of stuff jammed into one post. Oh also one more thing. can you also use ubuntu as a file server using smb? I'm assuming yes.. I have a few smb folders on my existing servers that I use to transfer stuff back and fourth to \ backups and whatnot

Yes