Building a Server Rack at Home

December 10, 2022
server rackmount

If you’re anything like me, you have a number of computers lying around your home office, serving as servers for various services. These likely occupy a number of traditional “tower” computer cases, with some even serving as nice footrests under your desk due to a lack of space to put them. Recently, I decided that I was tired of how much space these servers took up and decided to move many of them into a server rack.

For me, there has always been something exciting about datacenter-grade computing equipment. Perhaps it’s the elegeance of having everything stored in a rack, with flashing lights and easy access to every system without having to reach under a desk? Regardless, now that I’m an adult with a “real” job, I can afford to splurge on fun things every once in a while.

Finding a Rack

The first step in my build was to find a suitable rack to serve as the base of my home office network. For those new to this type of thing, the height of computer equipment racks are measured in RUs or “rack units”, which are defined as 1.75 inches (apologies to my metric-using readers - this is approximately 4.445 cm). Rackmount equipment is designed to take up a standardized amount of space on standard 19-inch wide racks, with height defined in RUs - usually 1U, 2U, 3U, or 4U. Now, one can easily find the real deal - a 42U floor-standing rack cabinet with locking doors - either new for a pretty penny or used but needing a truck to move. However, for both practical and financial reasons, I decided that this would be overkill for my setup and settled for an inexpensive 15U open frame rack.

Assembling the rack took a fair bit of effort, as the open frame design often resulted in rectangles turning into parallelograms. Additionally, I also assembled the it myself, without a second person to help, which resulted in difficulties holding screws. However, after a few hours, I finally got it assembled and ready for equipment installation.

Rack “Services” - Power and Network Access

While one often thinks of equipment racks in terms of the servers they contain, two key “services” that must be provided to these servers are power and network access. These are usually provided through power distribution units (PDUs) and “top of rack” network switches, respectively.

A PDU is essentially a fancy power strip that can be mounted on the rack with the rest of the equipment, with some even featuring load monitoring and network management interfaces. PDUs can be replaced or supplemented with uninterruptable power supplies (UPSes), large batteries that can protect against short outages or brownouts (drops in voltage), if one so desires. However, I decided to stick with a simple PDU without any special management or monitoring interfaces. I also decided to forego a UPS for the time being, although I might add one later.

We need a network switch to connect the servers within the rack to our network. One can get a fancy managed switch that would allow you to split up your network into VLANs, but I decided to get a cheaper unmanaged gigabit switch, which is more than enough for my current needs. If this was an enterprise network, I would probably have gotten a switch with faster uplink ports (e.g., 10 Gbps), but since my wired home network is only gigabit (as I imagine most are at the time of writing), this would increase my costs without any performance benefit.

I mounted both of these devices at the top of my rack, with the switch in the front and the PDU in the rear. This conserves rack space, as both devices together only take up 1U of my 15U rack.

Building the First Server

Now that the rack structure, power, and network access are out of the way, it’s time to build and install the first server in the rack. I decided to build a network-attached storage (NAS) server as my first rackmount server.

Like the PDU and switch we installed earlier, rackmount computer cases are also measured in RUs: usually 1U, 2U, 3U, and 4U are available. The service provided by this server - large amounts of storage - required that I use a larger rackmount case to hold the hard disks, so I settled on a 4U case. A 4U case also allowed me to use a standard ATX power supply unit (PSU), which I already had lying around. I also had a motherboard/CPU and enough RAM lying around, meaning that I only needed to spend money on the case and the hard drives.

Building the server into the case was rather trivial and much like building a traditional PC. Based upon my prior experience with rackmount equipment having loud fans (noise doesn’t really matter in a datacenter environment), I bought silent fans to swap into the case. However, after I plugged it in for the first time, I was pleasantly surprised to find that the stock fans were very quiet, so there was no need to replace them.

Since this server was intended to be a NAS, I needed to install a large amount of storage. I swear by Western Digital hard drives and never build systems with anything else after some bad experiences many years ago with other manufacturers - therefore, I chose WD Reds for my NAS. For now, I stuck with 20 TB of total capacity using five 4 TB hard drives. After installing Ubuntu 22.04 on the system, I set up a ZFS raidz2 volume, which can tolerate two disk failures - this reduces the total storage of the system by about 2/5, but it is worth it to ensure reliability. This volume is shared over the network via both NFS (for Linux) and Samba (for Windows).

Installing the Server

Heavier equipment is attached to racks with fasteners known as “rails”. Traditional slide rails allow you to slide the server all the way out of the rack, while still having it remain attached to the rack. I chose against using these because I was worried that my mostly-empty rack would tip over if I slide the server all the way out. Instead, I got “shelf rails”, which provide a platform for the server to rest on, instead of directly attaching to the server - this also ensures their compatibility with other equipment, as many slide rails are vendor-specific.

I secured the rails to the front and rear posts of the rack with rack screws and cage nuts, which was possibly the best decision I made during this process. I had used the inexpensive screws and bolts included with the rack for the PDU and switch, but it was very difficult to hold the nut in place while threading the screw through it, while also simultaneously holding the equipment up in the air. Rack screws hold the nut inside a rectangular “cage” that secures itself to the holes in the rack, holding it in place while you install the equipment and thread the screw. For heavier equipment like the server, I couldn’t imagine holding it in place while installing the screw, but it was a breeze with the rack screws.

Once I slid the server onto the shelf rails, I secured the front to the rack to ensure it wouldn’t slide out and connected it to power and the network. At this point, my rackmount setup was complete… for now.

Looking to the Future

As I mentioned above, I plan to expand my rack at some point in the near future. I have a few more servers sitting around in tower cases that would look much cleaner in a rack. Unfortunately, as I discovered during this process, rackmount equipment can be significantly more expensive than setting up a traditional system. However, there are serveral expansions and changes I plan to make in the future:

Parts List

Here I mention all of the specific items I purchased for this rack, not including equipment I already had on hand. Prices listed as of the time I purchased the product and do not include tax.

Note that I ordered the hard drives on Black Friday, so their cost may be notably below market.