It depends on the cost. If you are wanting to “roll your own” system I’m assuming you are very cost conscious. However, there’s a balancing act between cost of hardware, and your cost in time. Meaning that this is different for each person.
There’s a continuum that at one end has someone who is very inexperienced and unknowledgeable about a device or system (like a phone system, or automobile, or carpentry, or plumbing, or even the human body or mind, etc.) and someone who is very experienced and knowledgeable. My personality is such that I want to DIY in most things. So when I start working with a system I get very involved in it and progress along this continuum until I’m more knowledgeable than most people. Because of that I’m pretty immune from sales pitches for products that claim to “save you time” which basically means, I pay someone else for doing the work. But the downside of that is that I do end up spending a lot of time and energy on things. For example I still have all of the tile-cutting tools and so on I used when I retiled my bathroom and installed my own bathtub, even though I haven’t used them since doing it 8 years ago. Of course, doing it myself saved me around $15,000 most likely. But doing it myself also meant I made a few mistakes a plumber wouldn’t have made. However, I’m still using the bathtub and it hasn’t leaked and dry rotted out my house so there’s that. And, I can always do the job over again to fix the small mistakes.
So, unless you are like me, what I would use might not be appropriate for you. If you don’t want to move along the continuum to “very knowledgeable about FreePBX or phone systems” then get the PBXact appliance and pay someone to migrate over your config and make any fixups, or just do it yourself via the backup/restore method.
But, if I was doing it here’s what I’d do. For starters I’m a HP Proliant guy, I’m not into Dell servers. Now Dell has made some very fine servers in the past and I’ve speced and bought them for customers when I was working as a consultant but the thing you have to understand with servers is now nitpicky things are with them.
For example with HP Proliants, HP used to advertise a P410 hardware RAID card. But, it was super expensive. So they began advertising servers with a P410i RAID card. But the 410i IS NOT a hardware RAID card at all. It uses a software driver that HP only released for a few operating systems (none of them current) Microsoft kindly included the driver in Windows Server - (it’s still in Server 2022) but it does not support hot swap. So if a hard drive crashes, you have to shut the server down, replace the drive, then boot it and hope that a second drive does not crash during the rebuild cycle and booting.
Dell did the same thing and you have to really research things to understand the differences. I don’t have time to research for 2 different server vendors so I’ve concentrated on Proliants.
I’m also very partial to rack-mounted 1U servers. A half-height 24U server cabinet is very cheap on the used market I can generally find them for around $250. And it will fit a wide assortment of servers and switches and routers and rack mounted UPSes and the doors can be closed so people aren’t messing with the servers. However, I DO NOT use server cabinets in a server room at all. I used them in on-premise locations that don’t have dedicated server rooms. In a server room I use 2 post relay racks with center mount shelves and lay the severs on the shelves. It’s very easy then to access them and make recabling changes and swap out servers. When you see these stock photos of rows of cabinets in data centers just know they are doing it wrong and wasting untold number of technican hours dealing with cramped cabinets.
Anyway, I also buy used servers quite a bit for Linux/FreeBSD application projects. But when I do this, I also know I’m almost never going to get a hardware RAID card with the server so I’ll be doing software RAID. I also use LFF disks (I’ll explain why in a moment) and in a 1U form factor that means you get a max of 4 disk bays. Since RAID5 in a software array just sucks (it’s slow) and needs BIOS support for booting off of (supplied by the dmraid driver) and there’s no good Linux distros out there anymore that make installing a server using dmraid easy, nowadays my go-to reach for a commercial Linux application server on the cheap is to install 3 drives in a 1U system, then install Ubuntu Server, and set the first 2 drives up as a software mirror and the 3rd drive up as a spare, using mdadm. Ubuntu Server has a fantastic installer that enables you to do this. If I have an extra $500 then I’ll buy the hardware RAID card and battery backup, and install it in the server then install 4 drives and set it up hardware RAID5 with 3 drives and a hotspare.
Anyway I generally buy used servers sans drives. Many of them come with the drive carriers installed but no drives in them. I like this because the used drives in a used server are generally almost done with their lifespan. That’s why I concentrate on LFF setups and buy brand new drives separately. You can get new 1TB Western Digital Gold Enterprise quality 3.5" 7200 RPM drives for around $80 off Amazon.
If I’m doing a special application that does NOT save data in the app (such as a webserver that is manipulating a separate database on a different server) then I won’t use RAID at all I’ll just use a single Western Digital Black drive.
With HP Proliant Generation 9 servers, HP changed the drive caddy and added code into the BIOS that squawks if an HP branded drive is not used but only during boot. I had had no problems running aftermarket hard drives in these servers.
For Linux servers any Proliant generation G6 or later is fine but the G6’s had some build quality issues and if you have one of those servers and it dies - throw it away it’s not worth repairing. Sometimes they work fine and last decades other times not. For Windows Server 2022, anything Gen7 or later will boot on it even though HP doesn’t support Server 2022 on anything other than Gen 10 hardware.
Now, if you want to build a server on PC Desktop gear then literally any mid tower elderly “workstation” with a Xeon, or any Generation 7 desktop PC mid tower will work as long as it has 2 drive bays in it. There will be a TON of that gear on the used market since Windows 11 supports minimum gen 8 (Intel) or later. In that case, you would do software mirroring and do good backups. And you would want to very very closely inspect the motherboards for bad electrolytic capacitors before using any of that gear.
My current pair of virtual server hypervisors that I happen to have 3 guest instances of FreePBX on each of them (for testing) are Gen 7 Core i5 Lenovo small form factor desktops, single disk drive and 16GB ram, running Ubuntu and KVM+qemu on. What is funny is just for fun I booted a Windows 11 instance on one of them to demonstrate KVM. KVM can virtualize gen 8 hardware on gen 7 hardware and Windows 11 will install without complaints.
