Hello, I have some experience using Debian in NAS, but none with TrueNAS.

Before anything: BACKUP !

If possible, make a full copy of your pool onto external drives, or another NAS or anything else. If it is not possible to get enough spare storage soace, then at least backup the things your really care about (personal photos, important projects, password database). Just make sure you have a valid backup in case things go terribly wrong ! I am sure everything will go well, but this will give you additional peace of mind.

Setup Debian for NAS use

There are a few things I can think of, many might be obvious, anyway:

1. Install and configure network file sharing protocols: Samba (files sharing compatible with Windows, Linux, Android and others), NFS (more like network drive)
2. Install: S.M.A.R.T monitoring tools
3. Choose and configure filesystem. I have been using BTRFS, but since your pool is ZFS and you probably don’t want to format and start from nothing, I think you are already set on that one. I believe this is extra configuration as it doesn’t come by default on Debian.

More advanced things:

1. Setup SSH for remote connection with the terminal
2. Install htop or btop for system monitoring in the terminal
3. wireguard is a very nice VPN, it’s easy to configure on all platforms in order to access your NAS from outside your home

Power optimization

1. Enable C-stats in the BIOS (warning in case your CPU is a 1st gen Ryzen, do not activate)
2. powertop is an utility to optimize power saving settings (I’ve not bothered with this until now)
3. hdparm is an utility to manage and configure hard drives, you can use this to configure automatic spin-down after some time of inactivity, this is a bit tricky though.

Dashboards, UI, frontends

1. OpenMediaVault is the first one that comes to my mind. It’s actually a Linux distro based on Debian with a web interface that allows you to do all the NAS relevant confirmations from the Webbrowser. It can also be installed on top of an existing Debian install. I have used it a long time ago.
2. CasaOS, similar in concept, I have not used it.
3. Another simple option to get started, get a monitor, keyboard and mouse. Install Debian with full desktop environment and configure everything in person. You can always go headless at a later time

Docker

You definitely want to install docker to run most of your services. Please, also add your local user to the docker group to not have to run everything as root. Useful services I use:

• Portainer: manage containers with a web interface
• watchtower: Auto-Update other docker containers
• Jellyfin: media Manager and player (similar to Plex)
• *arr, transmission, sabnzbd: sail the high seas
• gluetun: route containers traffic through a VPN
• caddy: reverse proxy, to access your container with sub-domain name, example: jellyfin.mycoolnas.net
• vaultwarden: redistribution of the Bitwarden password manager for self-loading with the premium features available.

Graphics cards

It’s been a long time I didn’t have to deal with NVidia. Debian comes by default with the nouveau open source driver, which works but may not give the best performance. I don’t know if it impacts transcoding performance. I suppose it doesn’t give your the NVENC codecs. Anyway, you can install the NVidia proprietary drivers and should be able to transcode.

Conclusion

Debian is a solid option for a NAS, it’s been serving me well for many years. It is set and forget. However. It takes time to setup and the terminal is going to be your main configuration tool unless you go for OMV or another distro specialty made for NAS.

Your main source of information shall be the Debian Wiki. You will find step-by-step guides to install most of the things mentioned above. The Arch wiki is also a good resource, keep in mind that some files may have different locations and package different names across Linux distributions, but configuration should be similar.

Best of luck my friend

This doesn’t answer the question you asked, but take a look at OpenMediaVault. It’s Debian underneath but already has pretty much everything you would need to do built in.

For my own curiosity, I decided to check the release notes. I thought it was weird that TrueNAS would remove SMART monitoring, but looks like they didn’t. Just got heavily changed what they’re doing with it. The new recommendation is to use a third-party tool which does what TrueNAS was doing with disk monitoring, but does it better.

The short of it is TrueNAS still has smartmontools binaries installed and still monitors SMART data from drives. Just doesn’t have the dedicated space in the UI anymore. It’ll still alert on SMART failures.

Link to Disk Monitoring in the relevant Release Notes (25.10):

https://www.truenas.com/docs/scale/25.10/gettingstarted/versionnotes/#smart-monitoring-and-disk-management-in-2510-and-beyond

Acronyms, initialisms, abbreviations, contractions, and other phrases which expand to something larger, that I’ve seen in this thread:

7 acronyms in this thread; the most compressed thread commented on today has 15 acronyms.

[Thread #997 for this comm, first seen 12th Jan 2026, 16:45] [FAQ] [Full list] [Contact] [Source code]

Here’s one more opinion for you.

Running a NAS on Debian is a great idea if you don’t mind being responsible for all of the details that TrueNAS abstracts away. One thing I’d consider in your shoes is to use Proxmox VE rather than vanilla Debian. I say this because PVE uses a kernel with ZFS built in, so there’s no fiddling with DKMS to get it to work; it just treats it as a first-class file system (including on root). Having said that, either is a perfectly good choice.

If you want a UI, I’d heartily recommend Cockpit, which is included in the repos (just apt install cockpit). If you go the PVE way, you’ve got a couple options. You could either virtualize your existing TrueNAS, passing through the disks or (and this is my preference) let the host handle all the ZFS stuff and create an LXC container that just deals with filesharing. You’d bindmount a directory from the host that could be shared out via SMB and this is where I’d use Cockpit to manage the shares.

The PVE route makes adding VMs and containers pretty quick. I haven’t run into any issues passing through a GPU to either a VM or LXC, which can then be used inside a docker container.

In answer to the common pitfalls question, I think the biggest thing I see is that it’s important to document exactly what TrueNAS is doing for you. Did you encrypt the ZFS pool? Make sure you have the keys to unlock it and arrange for your next OS to do so gracefully. Are you managing snapshots and replication in TrueNAS? Document and adapt that. Something like sanoid/syncoid can manage this on a Debian system. How about monitoring? Don’t forget to set up notifications for disk failures. Any other services you’re using? NFS, iSCSI, cronjobs? Take care notes of everything because that’s the stuff that’ll be easy to miss if you jump straight to overwriting your old boot disk.

imma give you another opinion and start out with the unhelpful statement of „what’s best for you is gonna depend on what you need“

I‘ve never used debian as my personal NAS, but did manage a debian cluster at work. Compared to TrueNAS and later TrueNAS in a proxmox VM, debian is a lot more effort and in that sense „a hobby“.

Things that TrueNAS just handles for me without much work:

• install correct and functioning legacy nvidia drivers into select docker containers. i used to use an old card and it worked like a charm. comparing that to my experience of manually installing nvidia drivers on debian, both on work servers as well as on old systems i found on the street, Debian is a real chore sometimes and requires fiddling where TrueNAS is a lot simpler.
• TrueNAS apps are awesome. the catalogue is limited and sometimes it’s annoying how Truenas abstracts important things away (like the config file of HomeAssistant), but they are very useful too. they tend to be well-configured, updating is pretty and easy as is installing. you get automatic snapshots and rollback for each and every update. I have done systems administration as a hobby, but i kinda want my NAS to just work and that reliably. in that sense, Truenas has been better than debian for me.
• setting things up can be annoying on truenas, but most is set and forget. I set up smart tests and they just work now. same for snapshots. configuring pools and vdevs is pretty easy and intuitive. this also is the case for harddrive power profiles and spindown. i‘ve never had to do this on debian, so all i can say is that truenas makes it all very accessible.
• monitoring is easy-ish… if you wanna monitor from within the truenas UI, you’ll be pretty happy. there’s lots to see. some things you for some reason don’t though, and exporting makes you see even less info in some places. it’s a bit weird…
• re-silvering is very simple
• data replication is very nice. i’m using pcloud which has a somewhat annoying linux client. it’s a flatpak that only launches if it has a wayland (or x) session it can attach to, to display a window. kinda stupid if it’s a headless system or if i’m remoting into my desktop. still, truenas has me covered even in that regard as they can pull or push data (optionally well encrypted) to a variety of providers, including pcloud.

there probably is lots more, but i can’t think of anything else as of right now. I’ve used „plain“ Truenas scale for over a year and then switched to proxmox with a truenas VM when i built a new nas. the transition went pretty smoothly and i really like it. it does however add a layer of complexity you must be willing to deal with.

all things considered, i would like some things about truenas to work differently, but i would never wanna trade it. proxmox is very cool, and i like using it with a truenas VM, but i wouldn’t wanna use it without truenas i think. also i absolutely love debian and use it in many places. if i was running services on one machine and storage on another, id have the services on debian(or proxmox mby) and the storage on truenas, but as long as its just one device, its truenas.

additional thoughts:

• i’ve heard good things about unraid but never tested it.
• i’ve also seen many youtubers use CasaOS, but would recommend against it. i’ve not used it, but kept stumbling upon negative news in regards to it. it’s not as bad as omarchy/dhh, but it seems semi trustworthy.