Starting my (overkill) homelab

Thursday, October 6, 2022

I've set up a homelab finally! This is something I've wanted for a while and finally the timing was right. The right project came along to justify it, so I took the plunge.

Naturally, that leads to a few questions: What's a home lab? Why do you want one? And what is the shiny hardware? (That last one is the dessert if you get through the rest 😉.)

What's a homelab?

Oh, and is it "homelab" or "home lab"? Google Search Trends seem to indicate that it should be "homelab" in this context. When people search for "home lab" it's about science labs or dogs. When people search for "homelab" it's about computer stuff. So, that's the spelling I'll be using!

A homelab is, simply put, a place to experiment with technology at home! It can take a variety of forms, but that's the crux of it. Some people have homelabs of rackmount hardware, but it can be as simple as an old laptop or a Raspberry Pi.

Ultimately, people use them for a variety of different things. From "lab" in the word, you figure that it's a place for experimentation, not production. That doesn't always end up as the case: Some people run "home production" instead of "homelab", but it's a big tent. All are welcome.

There are basically two camps that I see homelabs fall into:

  • Used for hosting services: You'll see a lot of people hosting things for their own use. Things like Pi-hole for ad blocking) and photo sharing apps fall into this bucket. There's a lot of emphasis in this group on frugality and deal seeking.

  • Used for experimentation: You'll see people doing infrastructure and DevOps, security experiments, etc. This is the camp I fall into. I don't want my homelab to run anything that someone depends on. I'm also willing to spend a little more on it for expediency.

Why do I want one?

I mean, servers are fun. But I did say the right project came along to justify it. Or to rationalize it, at least.

Right now I'm attending Recurse Center, and one of my projects is making a key-value store. When I benchmark even just the protocol parser on my laptop, timing varies by 50% if Zoom is open. This makes for a bad test. I want to have a consistent test environment that I can run benchmarks on.

I would also like to have extra computing power to throw at things like tournaments of chess engines, since I'm working on a chess engine at RC as well.

I could do both of these using cloud servers, but... that can get expensive pretty quickly. This way I have an always-available local box that I pay for once and can use (and abuse). As a comparison, an equivalent AWS instance to what I got would cost the same amount after being on for 20 days. I could turn it on only when I need it, but in the long run having this machine is much more cost effective.

Also the hardware is shiny, and it makes my Rust builds significantly faster (30 seconds instead of 50 seconds for a full rebuild).

Okay, so what's that shiny hardware?

Okay, okay, I'll tell you about the hardware. I got a used Dell T7910 from PC Server and Parts. This was originally a video editing workstation, so it has a ton of PCI available, which will be handy for storage. Inside it, it has 2 Intel Xeon E5-2690 v4 CPUs (28 cores / 56 threads) and 128 GB DDR4 registered ECC RAM. I also have a paltry 1 TB SSD, which I plan on using as the boot drive but eventually augmenting with spinning disks and NVMe SSDs in those totally extra PCI slots.

"But Nicholas, that's ridiculous. That hardware is so overkill."

Yes, you're not wrong.

But it's shiny, and it'll last me a long time. It's accelerating my Rust builds and that's actually a real productivity boost. And it was cheap. It's a used workstation from 2017, so it's much much cheaper than new hardware.

How did you set it up?

Okay, so this is the saga, and it was painful. At first, I wanted to set it up with Proxmox so that I can provision VMs. And I wanted to do that provisioning with Terraform and Ansible. This wasn't an entirely spurious decision: I wanted to be able to benchmark things in isolation, and thought that would be a good approach.

Ultimately, it was a very painful decision, though. I never quite got things working and I was having really weird network issues, where I could not initiate outgoing connections from the VMs. And eventually I broke things so badly, I couldn't even ssh into them!

In the end, I realized that I didn't... really... need to do this? Why am I doing Proxmox again? Oh right, because I thought it was the "right" way to do it. No, no, that's okay. I'll do things the quick and dirty way 😀.

Instead of all the fuss, I just installed Fedora on it and called it a day. If I want VMs, I can explore things like Firecracker in the future, too!

Well, that was the end of the first part. But I couldn't get the thing to boot consistently! I had to mash F12 to get into the boot menu every time, because the drives connect through a SAS RAID controller. This controller permits direct mount of drives which aren't in RAID, but it seemingly does not permit default booting off one. Sigh. This is a big problem for me! If the power goes of and I'm away, I want to be able to wake the computer with a WOL packet, then have it come back up.

Fortunately, the solution was pretty straightforward. A fellow Recurser pointed out I should probably just connect that drive directly with SATA instead of through the SAS array controller. I could... but there are only two SATA ports on my mainboard and they're both in use! It turned out that the second one was not in use, but had a cable plugged in and cable managed into the back of the case for exactly this sort of use case. I plugged in my boot drive to that instead and everything came on! Reboots are consistent now, and it always comes back on.

Should you make a homelab?

I don't know! It depends. If you have something you want to use it for, by all means! It can be rewarding and useful. It can also be a new hobby that sucks up a bunch of your time and money.

Gamble wisely.

Thanks to fellow Recurser Mikael Lindqvist who paired with me on writing this blog post! It was a super fun way to get a post written, and I'd recommend trying it.

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