Server for working archive: NAS & self-assembly?

Question

Data archiving

For a small organization (10 jobs), it was necessary to archive work data with simplified access via SMB (mainly psd / ai layouts - employees will throw them into the shared folder themselves). The main goal is to create archive copies of this folder for the last two weeks. The total amount of data is up to 2TB. And for all this to work without constant administration, as there is a crisis in the country - a small organization has no money for a permanent administrator. Max 30 thousand allocated for equipment (with hard drives).
The first thought was - to collect the server on Linux. Something like this:
- computer: 4GB of RAM, 600W PSU, a mother with an Atom CPU on board (preferably without fans, so that there is less discussion)
- a system disk with server Linux with SSH service
- 1x2TB HDD for a folder opened via SMB (we will archive it )
- 3x2TB HDD protected from access via SMB combined into a single partition using one of the available technologies: RAID0 / LVM / mhddfs
- and a cron bash script that will make an archive once a week and delete old archives
- there is still an idea to make additional copying to cloud storage (for reliability, you never know - a flood), but I'm afraid that a 4TB cloud will be expensive.
The second is a ready-made network storage. The price looks attractive, and the ready-made management software also seems interesting. But there is one very important problem - I have never seen or configured a good NAS. And I'm not sure if he can do the same (or better).
So the questions are:
1. NAS or Server?
2.if the server, as for you, is such a server suitable or would you build something else?
3. if NAS, which one can you advise for my needs, without any nonsense like DNLA
4. what is the best way to combine HDD into a single section: RAID0, LVM, mhddfs and why?
5. what do you think about the cloud, advise inexpensive options for setting up under linux from the console
6. maybe there is another idea how to organize all this?
ps Regarding archiving and SMB, there is a possibility of infection with a virus (for example, a cryptographer), which is why it should be archived to another drive that is not accessible over the network.

Answer 1

1. server
2. any old iron will do, but not an atom and ONLY with active cooling!
3. stupid pieces of iron, they only eat electricity. I mean those that cost up to 30k
4. not raid0! never! NO! I did not use LVM, but mdadm is a battle-tested thing with crashes and a complete asshole. raid10
5. Clouds do not exist, and those that can position themselves at least a little like that, then there will be an exorbitant price. for such a backup, it’s easier to rent a VPS and merge data there.
6. you need old hardware (fire someone and take his PC), buy a flash drive , buy 4 disks for raid10 of such a volume that your 2TB + 2TB * <storage time>, i.e. Roughly you need 4TB disks so that you have 1 original and 3 copies (3 days or 3 weeks or 3 months).raid10 Put linux
on a flash drive, assemble mdadm raid10 from 4 disks, divide them into 2 sections: 2TB and the rest? and forward. Such a scheme is more reliable.
What disks? I recommend WD, some would say hitachi. But the main thing is not to take segates :) And their price depends not only on the volume, but also on the speed. And the speed will depend on the grid and on the mother with the process. so in the case of old hardware, wd green will do as well :)