Hello Friends
If you have the need to buy a computer as a server
I am assuming there is a some place as Amazon or Tom Hardware where exists a variety of servers (PC, MiniPC) according the manufacturer (HP, DELL) and models based on RAM, processors and SSD technology (as RAID etc).
I hope you see my point (and yes, the OS to be installed is Linux 
to execute Java 
and Spring 
apps)
Best to all
Amazon is a good source. Newegg.com is another one. Be sure to search for refurbished machinesâmany used ones are perfectly usable.
I second that.. a machine a few years old will most likely run Linux without the driver issues that frequently occur with brand new hardware.
For a server , I would look at a desktop tower⌠they are cheaper than laptops and more maintainable.
Last time I bought a system to run as a server was on e-bay - refurbished Dell Optiplex SFF (itâs tiny but still has a half height PCIe GPU slot)⌠Check the reviews of the seller before committingâŚ
Itâs my JellyFin Streaming media server⌠was about $400 AUD⌠16 GB RAM (single DDR4), 256 GB SSD, no GPU (onboard graphics enabled) and Win11âŚ
I wiped Win11 off the SSD - added another 3 x 4 GB RAM (for a total of 28)âŚ
Added my Intel Arc A310 GPUâŚ
Installed Debian 13 - initially with Mate DE⌠Installed JellyFin - connected it to the media on my NAS - started it transcoding all my Media (Movies, TVShows and Documentaries)âŚ
Disabled Mate DE and itâs now a headless server - the discrete GPU is used by JellyFin to transcode content âon the flyââŚ
Thereâs actually very little difference between a Linux desktop and a Linux server⌠Is there even any? Way back when - when UNIX was the king of âworkstation O/Sâ - many users ran an X desktop - but also âservedâ⌠and some even acted as the X desktop rendered on remote X servers (i.e. the binaries executed on userâs desktop UNIX machine, but display on remote X terminals - note: an X terminal is actually a âdisplay serverâ).
The main difference between Windows server and desktop - is - licensing and max number of users⌠thatâs a $$$ thing - Linux doesnât care too much about $$$ and licensing 
- way back when there was also a CPU limit and a RAM limit separating Win desktop and serverâŚ
Some UNIX systems were a PITA with licensing too - SCO was famous - you had to pay double again if you wanted SMP (dual CPU) and then something outrageous to go from 16 users to 32⌠DG-UX was also similar like that - i.e. a default install only allowed 2 simultaneous users!
For a file server you might find more than the average number of SATA ports useful. ⌠but yes, very little difference. That is why a refurbished desktop is a good buy for setting up a server.
I added an 8 port sata card to my desktop⌠that gives me loads of disk flexibilityâŚ
Not sure where youâre based Manuel, but I normally poke around Currys Business (if only to see whatâs out there as theyâre normally quite dear), manufacturer sites, GumTree/FB marketplace, CEX, and my local repair shop - theyâve always got loads of NAS kicking around. Seems like the second hand market around me is flooded with them.
I ended up building a mini ITX in the end as bang for buck went a lot further when I was looking.
Tried installing it in MX. Canât figure out how to make it work.
It is a client/server thing.
You need the server in MX , and a client in your phone or whatever.
I found out that it requires systemd, which isnât in MX. I guess I donât really need to sample it.