TrueNAS vs Debian

TrueNAS is a propose built solution.

You'll need to use it the way it's designed, which is extremely capable, but reading the manual is mandatory or you'll do it wrong and then it will suck. I know this.

There's TN Core, and Scale. Ones based on FreeBSD, one's Linux. You can compare for your needs.

TN can be an enterprise solution if that tells you the capability.

Edit, it's meant to be a storage solution. Scale adds containers. It's not great IMO as a general purpose server OS .

Maybe have a look at Proxmox. It's a Debian-based hypervisor with a web UI and ZFS support. However, while many people host Docker on it, it's not shipped with it by default.

TrueNas scale is a little heavier because it is a kubernetes implementation, but it is amazing.

The capabilities and possibilities are spectacular, and the maintenance required to keep all of your applications up-to-date is so easy that I no longer think about it.

Don't use TrueNAS for anything but a NAS

What do you need the webUI for? What's the use case? Here are a couple for you:

For simple file management and sharing, you may use FileBrowser. It's a single binary written in Go, just download and run.

If you're looking for a more advanced and generic server management solution, then Cockpit is a good option. It's available from Debian's repositories and provides a UI to manage users, storage (including RAID), firewall, system services and even virtual machines. Can also manage Samba shares.

Cockpit uses the same system tooling you would use from the command line. You can switch back and forth between Cockpit and whatever else you like. It wont pollute your system like other solutions and there are dozens of extensions for it.

I recently installed TrueNAS in Proxmox in this interesting Ouroboros-like configuration. So far it's been great.

OpenMediaVault is a Debian server with a Web UI.

I'm going to give a shout out to Ironicbadger over at https://perfectmediaserver.com/

One of his most recent builds was on promox

I've been running his 2017 version of Debian with docker-compose - zfs and mergerfs. And it's been rock solid for ages and ages.

Truenas scale is Debian, if you just use it remotely it may be a good bet. If you may use the server as workstation (e.g. desktop) then you better use Debian itself (or both, as VMs under Proxmox). Managing ZFS is super easy, just create a couple of volumes with small and big blocksize, in either cockpit or whatever web ui. You may also switch OS (e.g. disaster or play around), and recover these effortlessly with zfs import command from CLI. Good luck!

I'd just do omv. It's headless debian with web ui.

portainer.io with debian gives you a web UI if that's the only thing stopping you.
There's a Community Edition (CE) here: https://www.portainer.io/install