Storage Upgrade/Expansion Trouble

[SevenDaysOfFire]

I apologize in advance if this is somewhat long-winded, but I'm still learning and have far too many questions..  Bought some new hardware and I'm not sure if I can use it the way I had hoped.

Like the description states, I'm looking to increase my current storage capacity in a way that allows for expansion in the future if needed, and that hopefully also has some sort of redundancy in the inevitable event of a drive failure down the road.

My current setup has my Jellyfin installation as a docker container on an Ubuntu VM, in Hyper-V on a Windows 2019 server.  All my storage (just about 16tb of usable drive space) is in a separate NAS box I built running TrueNAS, but I'm quickly running out of free space and I'm not really a fan of how you add capacity to a current pool with ZFS/TrueNAS.

To remedy this, my thought was to buy a new server with enough HDD space so that I would no longer need the NAS.  I found a great deal on a Dell Poweredge R720, but in my excitement to upgrade I didn't read up on the difference between the R720 and the R720XD..  So now I have an R720 with 8x2TB 2.5" drives, which once I RAID5 is less capacity than the NAS I'm looking to leave behind.

My desire to no longer use the NAS is rooted in the acquisition of a sizeable 4 post server rack and wanting everything neatly mounted inside, instead of having a separate PC case next to it filled with hard drives.

So now I'm at a crossroads with no clear 'best' direction forward. 

I'm thinking I could just keep the NAS and split my lbrary, movies on the server and TV shows on the NAS....this would essentially double my storage capacity but splits my library and doesn't get rid of the NAS like I wanted.
I've been looking into an MD1200 storage array that I'm thinking I could just fill with all the drives currently in my NAS and some spares I have lying around to create an ISCSI storage pool.. But I'm not that familiar with that type of storage setup, and if I'm understanding correctly what I've been reading, the spread of 1tb, 3tb, and 6tb drives I have isn't the best for a RAID array (I've seen this referred to as a JBOD setup with no redundancy?). 

Looking around I'm seeing mentions of UnRAID, SnapRAID, and BTRFS.. but while SnapRAID looks like it'd do everything I'm looking for, I'm not sure if any of these options are better than the other.

And all of this leads neatly to related concerns about having to potentially switch file systems (ZFS/TrueNAS to Windows/NTFS, for example) and doing so without corrupting or formatting the 14tb of media I've already got..

Again I apologize for how long this ended up, but any information or suggestions are greatly appreciated, and I'm more than willing to provide more information/answer questions about my setup if needed.  Thanks!!

[Deleted User]

you could buy a single 16TB and dump the entire contents of your existing NAS on it

for personal use - i use jbod and just add multiple paths to each jellyfin library
- my redundancy (and safety net) is physical bluray discs, diligent administration and strict policies about old drives, 3 years is a limit for my drives and after 2 they become archival storage away from any main activity

for personal non-media use i have a single redundant backup alone

for business it's a different story, 3x redundancy minimum 'online' and an offline archived copy because you're dealing with databases that cannot be replaced

so it is really hard to speculate what will be best for someone else because the loss of time may be unacceptable where it is not to me


edit: in fact, just today i phased out 2 8TB drives - 1 s.m.a.r.t. started reporting bad sectors (everything was recovered safely), the other was an archive