Small Business Solution

I am looking to install a Server for a small business with about 10-15 users. I do not want to have them pay huge amounts of money for a Microsoft Server. I have seen some solutions like ClearOS and Zentyal. Anyone with any experience with these solutions or any other ideas would be great. I want something super stable that once setup I can leave alone. I don't want to have to charge them for me to fix something with inherent issues.

What is this server going to be doing?

Authentication/Domain
File Server
Antivirus Management
Email (future plan)
Remote Access (administration)
If I don't do a RA VPN then I will just port forward and use RDP from the server to the clients.

Separation of tasks. You don't want to have one server functioning as too many items in case of device failure. I say that, however, my primary DC does file/printer functions as well.

What kind of budget do you have? If you have ~800 for a server OS look at Server2012R2. You get 3 licenses for that cost for Hyper-V purposes. 1 license is the bare metal machine, 2 Hyper-V servers.

1 VM does DC, files, print. The othe other does antivirus and RDP functions (although you can get around this with a VPN and RDP to their workstation) and setup some windows7 machine with Mercury email.

Raid 10 some drives, setup monitoring to email you when something is wacky and you're done.

The budget is next to nothing. I plan to use an old desktop with decent specs. I am looking for mostly open-source solutions.

If you are doing a domain for an active directory like service. microsoft is the best option. Do not cheap out you will regret it later.

if this is a file server you will need at the very least a form of raid, and a backup server/unit. You do not want to be responsible for them losing all their files.

At the minimum you are looking at several hundred just for a server with drives. There are sites out there that do refurbished with warranties. such as www.savemyserver.com.

Do they have a hardware firewall? if so this should have vpn capabilities but it might be just between itself and not a vpn server.

What @HelloMrOwl said is pretty much what you are going to do if you are on a budget.

I'd love to help you out but I work in the medical corporate world so my knowledge is almost pure windows when it comes to server hosting.

The best advice I can give you is don't cheap out when you're storing data. Upfront cost is always better than aftermath cost.

Thanks for the reply. I do IT for the Federal sector and I know a lot about windows as well as Linux. I just wanted to gather others thoughts and ideas on some alternatives since MSFT is very expensive.

There is no way they will spend the kind of money it takes to do a fully redundant setup with hardware firewalls and such. Like I mentioned there are 10ish users. I may just do a super cheap home server type setup for proof of concept and try to convince them to drop some dollars later on. Thanks for the advice.

Well you can try to do LDAP, and use a stable OS such as Debian, CentOS or Ubuntu Server. I have never set up LDAP so you would have to ask someone else about that.

And always remember to "Cover thy own ass" especially when it comes to other peoples data.