Infrastructure
Hardware Advanced #3: Memory Deep Dive — Page Cache, THP, and Bandwidth
A tour inside the kernel memory machinery: the read and write paths through the page cache, the latency spikes THP creates, explicit hugepages and the TLB, how swappiness is actually implemented along with zswap, and the memory bandwidth bottleneck that keeps throughput flat even when cores sit idle.
Hardware Advanced #2: eBPF Observability — Seeing the Tail the Average Hides
eBPF is a technology for tracing system events directly with small programs that run safely inside the kernel. This post covers reading the latency distributions and tails that averages hide with biolatency and runqlat, a map of the BCC tools, and the overhead caveats for production use.
Hardware Advanced #1: CPU Microarchitecture and perf — Why the Same 100% Isn't the Same
Two CPUs can both read 100% utilization while getting very different amounts of work done. This post uses IPC, cache misses, and branch mispredictions to read the microarchitecture behind the utilization number, and shows how to tell memory stalls from genuine compute saturation in perf stat output.
Hardware Intermediate #9: Hands-On: Diagnosing a Slow Server — Series Finale
A diagnostic walkthrough that starts from a "the service is slow" report and narrows down through the four resources one by one. Define the symptom, check each resource, confirm the hypothesis, apply a fix, and re-measure. We close the Hardware Intermediate series with the principles of tuning.
Hardware Intermediate #8: GPUs and Accelerators — The Fifth Resource of the AI Era
The bottleneck of AI workloads often lies beyond the four resources. How a GPU works differently from a CPU, the VRAM and HBM that determine model capacity, reading nvidia-smi, and sharing a GPU with passthrough, vGPU, and MIG — all from an operator's perspective.
AWS Certified CloudOps Engineer - Associate (SOA-C03) #15 Full-Scale Multiple-Choice Mock Exam — 50 Questions + Explanations
The final post of the SOA-C03 series. Matched to the real exam's domain weights (monitoring 22% , reliability 22% , deployment automation 22% , networking 18% , security 16%), you solve 50 questions and find your weak domains through each question's answer and explanation. Solve them on the clock, then go back to the relevant domain post to shore up any gaps.
Hardware Intermediate #7: Storage Networking — iSCSI, FC, NVMe-oF, Multipath
Once the disk leaves the server, storage becomes a network problem. The trade-offs between iSCSI and FC, NVMe-oF for the NVMe era, multipath operations that take charge of path redundancy, and the connection to cloud block storage.
AWS Certified CloudOps Engineer - Associate (SOA-C03) #14 Exam Tips and Common Operational Scenario Mistakes
The fourteenth post of the SOA-C03 series, a final review right before the exam. It covers the common pitfalls that cut across domains, the keywords that separate similar services, how to read scenario questions, time management strategy, and a final pre-exam checklist.
Hardware Intermediate #6: RAID in Operation — Rebuild, Scrub, and Backups
The real test of RAID begins after a disk dies. Why the rebuild is the most dangerous window, the URE problem that makes RAID5 risky in the era of large disks, what hot spares and scrubs do, the write cache and its battery, and why RAID is not a backup.
AWS Certified CloudOps Engineer - Associate (SOA-C03) #13 Domain 5-2 Security — Config, CloudTrail, GuardDuty, Security Hub, KMS
The thirteenth post in the SOA-C03 series covers detection and audit, plus encryption, the second axis of the security domain. It covers how to audit API calls with CloudTrail, how to evaluate configuration compliance and auto-remediate with AWS Config, GuardDuty threat detection, the unified score in Security Hub, and KMS key operations.
Hardware Intermediate #5: Measuring Storage Performance — fio, Queue Depth, Inside SSDs
Catalog IOPS only makes sense under specific conditions. How to measure under the conditions of your own workload with fio, the trade-off between queue depth and latency, and the internals — write amplification and TRIM — that make the same SSD perform differently today than it did yesterday.
AWS Certified CloudOps Engineer - Associate (SOA-C03) #12 Domain 5-1 Security — IAM,Organizations,Multi-account Operations
The twelfth post of the SOA-C03 series covers identity and multi-account governance, the first topic of the security domain (16%). It covers IAM permission operations, the credential report and IAM Access Analyzer, MFA enforcement, AWS Organizations and SCPs, and multi-account standardization.