How reasonable is it to make a "server" from a regular computer (with a limited budget)?

Question

Computer networks

There is a task to put 5 servers in a small (15 employees) company. According to the requirements I calculated, the equipment is approximately the same - xeon e3, 4-8 ram, 250 hdd (os) + hdd (raid). The price varies by 40-60 tr. for each, total 200-300 tr. This is a lot, and can stretch for several months if you enter it in parts, but you need it as always "yesterday".
Does it make sense to start thinking in the direction of ordinary PCs?
Some PC assembly Core i5 2310, 8 ram, 500 hdd will cost 14500 + additional hdd (raid software) + something else = 20-30 tr
Total amount is reduced by 2 times
Tasks that require servers:
1. domain controller + network security (firewall, antivirus, etc.)
2. application server
3. file server
4. backup server
5. server backup isolated from the network (archive)
Here I sit and think, but will I regret later if I take ordinary PCs. Still, I have never seen ordinary PCs in the role of a server in small businesses.

Answer 1

um, for example, I have all the servers on ordinary PCs, it started like that, when the whole company was placed in one office, now there are about 50 people in the company, a server room has appeared, several sites on the Internet are spinning and everything is still on ordinary PCs

Answer 2

1) Why do you need a domain for 15 people? :) Even Microsoft recommends raising a domain from 20 machines (we make allowances for their interest in sales), and according to experience, less than 50-100 makes no sense. My experience is really about 10 years ago, maybe I'm a little outdated :)
2) Why do you need a separate application server for 15 people, a separate file server, 2 (!) Separate backup servers? Moreover, in such a strange configuration - os on hdd (and not ssd), almost without memory - but xeon. If you want to twist the terminal 1C there - xeon will not save, obviously there is not enough memory. My home computer is more powerful than what you write 4 times)
We had a local area for 350 machines, there were 2 domain controllers, but at the same time they performed a bunch of other functions - an antivirus control center, a file server, and backups of critical things, and all sorts of network licenses for specific software were spinning there, etc.
Separately, there was a * nix machine assembled on the knee of what it was, it had a proxy, traffic accounting for users, a firewall.

Answer 3

Make a private cloud from ordinary machines. If it breaks, migrate the image to another machine.

Answer 4

Can you do it on virtual machines? And there is not enough information about the load. What will the backup server do? You can get by with the built-in archiving service, if win server, then point 4 is not needed. Combine a domain controller with a file server, Instead of point 1, buy UTM. Make a backup on a NAS.
Total remain 2 servers, UTM and NAS.

Answer 5

In general, to everything you wrote about in the question (before the question itself), you had to come somehow. It turns out strange, all the servers that you administrated were immediately "serious"? And never used regular PCs?

Answer 6

1. You need two servers (can be based on computers) and a virtualization system. The best to start with is vmware ESXi 5.5u2
2. "network isolated backup server backup (archive)" how can it be isolated from the network if it is backed up over the network?
Backup can be done on a removable USB drive, when it is removed, it means isolated. Also make a backup of virtual machines from server 1 to server 2 and vice versa. In the event of a breakdown of one of the servers, you can start (manually or automatically) everything on the second one (provided that there is enough hardware capacity).
P.S. I also recommend not to use RAID and a bunch of desktop disks with a small budget.
A normal controller costs 20-30 thousand rubles.
Look at the SSD. From inexpensive, reliable and fast samsung 840pro, sandisk x210. Even more reliable is the intel 3500 or 3700.
In total, the computer has 2 SSD + 1 or 2 HDD for backup.
Cards compatible with vmware esxi - intel desktop gigabit adapter EXPI9301CT - 2 pieces per computer.
HDD Hitachi, HGST - the least broken.
Computer based on Q87 chipset + CPU i5 \ i7 with vPRO support + 32 GB of RAM.
Desktop case in places for 7-8 disks.
*Vpro - technology for remote control of hardware and software. If the computer freezes up, you can remotely reboot it, turn it on, rearrange the OS.
Also look at Veeam backup and replication software.