Series / #dc
Inside the data center
Nine parts on the physical side of infrastructure — what a cage, a cross-connect and a pair of remote hands really are, written for people who only ever meet servers over SSH.
- Parts
- 9
- Words
- 18,855
- Read time
- 96m
Start part 0 not started
Contents
- 00 The vocabulary I have never racked a server. I have opened a lot of tickets asking someone else to. That is the normal shape of this job now. You are a competent Linux engineer, you own machines that live in a building you have visited maybe twice, and every physical act on…
- 01 Anatomy of a rack A 42U cabinet does not give you 42U of usable space, and the sooner you internalise that the fewer awkward conversations you will have about why the new server does not fit. This part is the physical frame: what the numbers mean, what holds equipment in, why…
- 02 Power, A-side and B-side You are sold a 30 amp feed. You can use 24 of them. If you also want redundancy, you can use 12. Power is the part of the datacenter that punishes vagueness hardest, because the failure mode is not a warning in a dashboard — it is a breaker opening and half a…
- 03 Cables, optics and transceivers "Send me a 3-metre DAC" is a complete, unambiguous, orderable request. "Send me a network cable" is not. This part is about being able to say the first thing. The three ways to connect two ports Every high-speed link in a datacenter is one of three physical…
- 04 Out-of-band access Every remote hands ticket you do not have to open is a win, and out-of-band access is how you avoid most of them. There is a second computer inside your server. It has its own CPU, its own firmware, its own network stack and its own IP address, it runs on…
- 05 Where the switches live Your server's NIC cable probably travels about two feet. That fact shapes more of the datacenter than anything else in this series. This part is where switches physically sit, why that choice was made, and what it means for the cabling in your cabinet. The…
- 06 Leaving the cage Everything up to this point stayed inside your cage. This part is about the handful of strands that leave it, and about the paperwork that governs them — because the paperwork is genuinely the hard part. The chain, end to end Almost all confusion here…
- 07 Directing remote hands The technician reading your ticket is standing in a cold, loud room, in front of forty identical black boxes, wearing gloves, holding a tablet. They cannot see your monitoring. They do not know your naming scheme. They have another six tickets after yours…
- 08 The cheat sheet Everything in this series on one page. Bookmark this one and skip the rest. Vocabulary, in one line each Term What it is U / RU Rack unit. 1.75 in / 44.45 mm of vertical mounting space. Cabinet Enclosed rack with doors and sides. What colo actually sells you…