Infrastructure
Docker Basics #3: Images and Containers — build, run, ps, logs, exec
The day-to-day Docker CLI commands in one place. build options, the run flags you actually use (-d, --name, --rm, -e), and the lifecycle that runs through ps , logs , exec , stop , rm.
RHEL Basics #1: What Is RHEL — From Fedora to RHEL, plus AlmaLinux and Rocky Linux
Fedora is where new technology gets tried first; what survives flows into RHEL. CentOS Stream sits in the middle as a preview of the next RHEL, and AlmaLinux and Rocky Linux have settled into the role of free RHEL-compatible distros. Here's the shape of the RHEL ecosystem after CentOS, in one read.
Docker Basics #2: Writing Your First Dockerfile — FROM, RUN, COPY, CMD
Building your first image for your own app. Pick a base with FROM, prepare the environment with RUN, drop in code with COPY, and pin a startup command with CMD. One full cycle, on a tiny Python app.
Docker Basics #1: What Is a Container — VM vs. Docker Ecosystem
Why Docker — how containers differ from virtual machines, why Docker emerged, and a tour of the Docker ecosystem built around Engine, CLI, Compose, and Hub.
Hardware Basics #9: Reading Cloud Instance Specs — Choosing to Match the Workload
Dissect an instance name like c5.xlarge into family, generation, and size, then read a spec sheet by vCPU, memory, storage, and network to pick a type that fits the workload. This post gathers the series' four-resource knowledge in one place.
Hardware Basics #8: Cloud — From Owning to Renting, from On-Prem to IaaS / PaaS / SaaS
The shift of hardware from owning to renting, the difference between on-prem, colocation, and cloud, and how far IaaS, PaaS, and SaaS hide the hardware. The cloud seen through the lens of hardware ownership versus rental.
Hardware Basics #7: Virtualization and Containers — How One Physical Server Becomes Many
How a hypervisor splits hardware, the difference in how virtual machines and containers share resources, and overcommit — the reason cloud performance becomes unpredictable. The principle by which one physical server becomes many.
Hardware Basics #6: Network — Bandwidth and Latency, from the NIC to the Data Center
The most-confused pair in operations — bandwidth versus latency — the latency floor that distance imposes, and starting from the NIC, why the same AZ, cross-region, and the internet all differ. Understand the network as two axes, not one word for speed.
Hardware Basics #5: Storage ② Layout and Connection — RAID and DAS / NAS / SAN
RAID (0, 1, 5, 6, 10) that bundles disks for speed and safety, and the three ways to attach disks to a server — DAS, NAS, SAN. How these concepts were repackaged into cloud storage like instance store, EBS, and EFS.
Hardware Basics #4: Storage ① Devices — HDD / SSD / NVMe and IOPS / Throughput / Latency
How HDD, SSD, and NVMe differ, and how to distinguish capacity from the IOPS, throughput, and latency so often conflated with it. Why cloud disk options like gp3 and io2 diverge, all in one pass.
Hardware Basics #3: Memory — RAM, the Hierarchy, and What Happens When Swapping Starts
What RAM is and why it is volatile, the memory hierarchy from registers to disk, and how performance falls off a cliff when memory runs short and the system spills to swap. Understand memory as behavior, not as a capacity number.
Hardware Basics #2: CPU — Cores, Threads, Clock, Cache, and What a vCPU Really Is
The difference between cores and threads, why clock speed alone cannot compare performance, how cache governs speed, and what the cloud actually means by a vCPU. Understand the CPU as behavior, not as a spec sheet.