#Hardware
25 posts
Hardware Intermediate #4: NUMA — Memory Is Not Uniform
On a server with two or more sockets, memory access speed depends on where the core sits. NUMA structure, the gap between local and remote access, miss ratios as seen in numastat, and how databases and virtualization cope.
Hardware Intermediate #3: Memory Deep Dive — available, Dirty Pages, Container Limits
The one column that matters in free output, the dirty-page behavior behind sudden write bursts, what swappiness really means, and cgroup memory limits with container OOMKilled — memory as you meet it in operations.
Hardware Intermediate #2: CPU Deep Dive — Turbo, Throttling, Steal Time
The clock on the spec sheet is not a promise. Why turbo boost and thermal throttling make the clock swing, the steal time that eats away a VM's CPU, the cost of context switching, and CPU pinning — the CPU as it behaves in operations.
Hardware Intermediate #1: Reading Performance Metrics — Turning Slow into Numbers
If Hardware Basics gave you the mental model of the four resources, the intermediate series starts on the operations floor. It uses utilization, saturation, and errors as the three questions for reading metrics, and explains what load average and %wa really mean as signs of hardware behavior.
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.