I built this PC in June 2020, and I haven’t touched its hardware components since. I only know the date because it’s printed on one of the sticks I pulled out that night, and seeing it stopped me for a second. Peak pandemic, me putting a machine together on the dining table. Six years later it was still running everything I’d thrown at it, which is exactly why I never touched it.
The reason I finally had to was Wazuh.
My Proxmox host, lab0, was sitting on 32GB of RAM. I restarted it fresh, and it climbed right back to 63% memory utilization; on a normal day when I’m not touching anything, it drifts up to 70% or 71%. Almost all of that is one node. Wazuh was pulling around 18GB immediately after boot and creeping toward 30GB the longer it stayed up.
That’s what finally pushed me. It wasn’t that anything was broken; it’s that nothing new could ever get built. Every time I thought about spinning up another VM for a project, the math said no before I even got to the fun part. So I had to upgrade the memory.
Two G.SKILL Ripjaws V DDR4 sticks, 16GB each, to take the host from 32GB to 64GB. $239, which stung a little. If you’ve priced memory recently, you already know why: AI demand has RAM in a strange place right now, and DDR4 didn’t get a pass. Not an outrageous number for 32GB, but definitely a premium over what I paid for the original build.
Before I pulled power on anything, I did one small thing that I’d recommend to anybody about to do the same job. I went into the Wazuh VM options in Proxmox and turned on start at boot. It takes thirty seconds, and it means that when the host comes back, your important VMs come back with it. Then I shut the node down cleanly, powered off the machine, and unplugged it.
Where it started going wrong
Two open DIMM slots, two new sticks. I had this pegged as a fifteen-minute job.
The first one went in fine. Lined up the notch, pressed down, heard the click, felt pretty good about myself. I flipped the lever on the second slot, slid that stick in, and it felt locked, so I closed everything up, plugged the machine back in, and hit power.
Yellow light.
I gave it time, because I didn’t expect it to post instantly, and I kept refreshing the Proxmox page like that would help. It stayed yellow. Then, on a later attempt, it went red, and red is what actually worried me. So I looked both up, and it turns out the board had been telling me exactly what was wrong the entire time.
Solid yellow or amber on the DRAM light means memory failed the power-on self-test. Red means the system can’t detect a component at all.
Fine. Something’s loose. I powered down, opened it back up, and started reseating.
The thing I didn’t know about DDR4
This is where I burned most of the evening, and where the actual lesson lies.
I pulled the sticks and pushed them back in, and nothing changed. Did it again; still yellow. I was being careful, because these things are expensive and they feel fragile, and I kept thinking I was going to crack something. At one point I caught myself wondering if I was the problem, doing this on my office floor, in bad light, wearing jewelry, not grounded, which is a pretty complete list of what you’re not supposed to do.
I was the problem, just not in the way I assumed.
A stick can be locked at the bottom and completely loose at the top. It looks/looked seated, but it isn't.
DDR4 needs more force than feels acceptable, and it needs that force at both ends until each side clicks. Being gentle was why nothing worked. Once I pushed harder, every stick clicked twice, and suddenly they all looked properly seated in a way they hadn’t before. I had pushed one in earlier, and it wasn’t even sitting right, which is a little scary in hindsight.
So now everything was genuinely in. I closed it up, powered it on, and got yellow again.
The part that wasn’t the RAM
At that point I was lightheaded and out of ideas, so I went looking. I found people on Reddit describing the same lights and saying the fix was to reseat the big power cable that runs into the motherboard, which I hadn't touched once.
I grabbed my phone flashlight, which I should have done an hour earlier, and actually looked. The large connector was snug. The small one next to it wasn’t, and I’d been fighting it because I was going in the wrong order. There’s a little arrow stamped on it that had me second-guessing myself for a while, trying to work out which way it was supposed to point.
The small connector goes in first, and then the larger one seats on top of it and anchors, with a clip on the side. Once I did it in that order, it slid in and sat snug immediately.
Looking back, this is the part I’d want somebody to take from all of it. I was a hundred percent certain this was a memory problem, because memory was the thing I changed. It was partly memory, and partly a connector I never intended to move, and I only found the second half because I got desperate enough to stop trusting my own assumption. If you’re reading this thinking I was making it far harder than it needed to be, you’re right, and I knew it while it was happening.
Back online
I powered it on, and the light went yellow, then red, then white, then red again, then white, then green. I went through about six emotions in ten seconds.
Then the POST screen came up: ASUS TUF Gaming, total memory 65536MB.
It booted into safe mode, which makes sense after that many failed POST attempts and a few forced shutdowns. I went into the BIOS, checked the CPU temperature, confirmed DRAM status looked right, confirmed Proxmox was still first in the boot order, changed nothing, and saved and exited. One more reboot, and lab0 was back.
Proxmox reports 62GB usable rather than 64, which is normal. The BIOS sees the full 65536MB, and some gets reserved before the hypervisor ever counts it. Wazuh is now running around 59 percent of the 32GB I allocated to its VM, and that’s completely fine because it’s using what I gave it instead of squeezing the entire host. There’s finally room for the next VM.
Tailscale was the last loose end. The tail IP wouldn’t load at first and tailscale status reported it running but idle after all those hard resets. It came back on its own after a while, and by then it was the least of my concerns.
What I’m taking away
Turn on start at boot before you power down. Thirty seconds of prep so you’re not troubleshooting two problems at once.
Read the lights. Amber means DRAM, red means a component isn’t being detected. The board is specific. I guessed for twenty minutes before I looked it up.
RAM needs real force, at both ends. No click on both sides means it isn’t in, no matter how snug it looks.
Work on a flat surface with the light on. I did neither and made the whole thing harder than it had to be.
Question the thing you changed. I was sure it was the memory. The power cable I never touched was half the problem.
So, storage or a NAS?
The bottleneck has now moved, and now I’ve got headroom for the projects I’ve been putting off.
Storage is the next constraint. I’m on a single 1TB drive, and I keep going back and forth. I could drop in another SSD, which is cheap, quick, and solves the immediate problem. Or I could build out a mini NAS, which costs more and takes real work but gets the lab closer to something that actually resembles infrastructure instead of everything living on one disk. That’s also just a better project.
Still deciding, and you’ll be the first to know when I decide.
Two questions for you in the meantime. Would you have done this upgrade differently, and if so, how? What should I hit next: another drive or the NAS?
Until Next Time
That’s it for this one.
As always, keep learning, keep building, and keep thinking deeply about the systems we’re trusted to defend.
See you in the next one.
~ Day 💙
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