Debian is very well suited for application servers, web servers, file servers, hypervisors (personally, we use Proxmox for some hypervisors and this is based on Debian), and much more. It can run on various CPU architectures and scales well from large to small. We have Debian DNS servers running on Raspberry Pis, and large application and database servers running on powerful Debian installs in our racks.
If you want an OS that is rock solid, easy to manage, and predictable, Debian might be the OS you're looking for. The official packages are generally far from being bleeding edge versions, but this means that you are using packages that are battle tested and will not break compatibility at any point during its life-cycle. This, to me, is one of Debian's core strengths and a good reason for recommending it to others.
On the flip-side, the lack of up-to-date versions of various packages may be an annoyance if you actually do need to be using the latest version of such a package. If you need to be using more modern versions, you will need to remedy that yourself or look at an alternative distribution. Ubuntu may be worth a look, in this case, being that it is basically Debian with newer packages and some minor differences here and there.
Personally, I would not recommend Debian for a graphical desktop OS. You'll nearly always be better off with one of the Ubuntu flavors for a modern desktop with all the bells and whistles you'd expect with a GUI desktop.
We have many TrueNAS units deployed and they've served us well everywhere. Our most common use case is using it as storage backing for virtual machines. We have Proxmox talking to it, as well as having it acting as the hypervisor. We've never lost data with it, even when faced with multiple disk failures. We've also always found the performance to be robust and able to handle the needs of our clients. Our clients range from libraries, to medium sized enterprises and we've always been able to make it work, and work reliably.
The software has been amazing. It has saved me a lot of headache in the past few years. Also, it's nice to knowing that if any of our current Synology devices were to die I can have an iSCSI system up and running very shortly. I didn't give a 10 score because I find their support to be rather slow and pedantic. They test many things when the answer is right in front of them. The compute sytem (not storage) we purchased from them came with pcie gen4 nvme's. They didn't work, but rather than believe me about the spec's in the motherboard manual saying the onboard was pcie3 ONLY they shipped me 2 replacements until I showed them an old pcie3 device worked just fine. The part that rather frustrated me was the machine was claimed to have been tested / burnt in. How can this be true if the server won't even boot up into the BIOS?
Debian is one of the most well-thought-out, logical, and intuitive Linux operating systems you can use. Configuration, package management, file system layouts, etc, are all based on many years of usage, and it's very rare to find anything surprising or confusing in everyday usage. Package management and updates are handled by APT in such a way that once configured, you can almost guarantee your system will behave as expected for the lifetime of its service. Top-notch system integration provides all the tools you'd expect from a modern Linux system, with all the stability you demand from a demanding server OS.
The software is fairly straight forward and if you mess up the network interfaces you can login locally at the console and fix any issues that you may have had with VLANS etc denying you network access. There was a little bit of annoying issues when setting up multiple network interface cards. Rather than keeping one interface setup with DHCP, when you add a second one with a new network it disables the first. Which makes it impossible to login again. However if you wait it will revert. I learned after works that you need to set up the network cards and then go back and setup the first one again and THEN test / apply. After that it was pretty good. The summary of the devices is very nice to. You get an accurate snapshot of how well your system is doing as soon as you login
The support was responsive for opening cases. However I found solutions to simple problems took far too long. When we had a bad power supply and we had another with the exact same firmware version they should have sent replacement for both. We had to file another case for the other PSU that started dyeing the same week. They also had to do a lot of troubleshooting to replace the fans that were not behaving as they should. I'm not a home user. I know when certain things are failing and the silly hoops the jump through made it frustrating. However, once we finally got the problem identified we had parts shipped out via advance replacement which was nice.
The implementation went well after we got the boot drive working properly. The device was setup exactly as i asked with the hardware except for the boot drive. The reason I chose 9 instead of 10 was the boot drive put us back about a week for the part to arrive. I ended up using a personal drive to show them that they were wrong sending use the gen4 drives.
I chose TrueNAS (upgrading from FreeNAS) because of the small footprint, ease of use, and reliability of the ZFS file system. The file sharing protocols supported as well as the intuitive interface all make TrueNAS a great choice for business and hobbyists alike.
Using a TruNAS integrated solution has reduced support overhead compared to using custom hardware.
Being cheaper than full flash storage arrays, this unit allows for a good balance of speed with its use of SSD-based caching drives.
The reliability of the hardware/software integration means I spend less time troubleshooting and more time doing business. Coming from a custom-built solution it is apparent that IX Systems has done some extensive testing.
