Infrastructure
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.
Certified Kubernetes Administrator (CKA) #27 Full-Length Practice Exam — 17 Tasks with Solutions
The final post of the Certified Kubernetes Administrator (CKA) series. Work through 17 task scenarios that integrate every domain in the same flow as the real exam, then unfold each task's solution commands, YAML, and explanation to grade yourself. Sum the points against the 66% pass line and lay out a review path for your weak domains.
Certified Kubernetes Security Specialist (CKS) #20 Full-Length Practice Exam — 16 Tasks with Solutions
The final post of the Certified Kubernetes Security Specialist (CKS) series. Work through 16 task scenarios that integrate all six domains in the same flow as the real exam, then unfold each task's solution commands, YAML, and traps to grade yourself. Sum the points against the 67% pass line and lay out a review path for your weak domains.
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.
Red Hat Certified Engineer (RHCE) #19 Full-Length Practice Exam — 15 Tasks with Solutions
The final post of the Red Hat Certified Engineer (RHCE) series. Work through 15 task scenarios that integrate every domain in the same flow as the real EX294, then unfold each task's solution Ansible playbooks, commands, and explanation to grade yourself. Sum the points against the 210/300 pass line, check idempotency and FQCN, and lay out a review path for your weak domains.
Red Hat Certified System Administrator (RHCSA) #16 Full-Length Practice Exam — 16 Tasks with Solutions
The final post of the Red Hat Certified System Administrator (RHCSA) series. Just like the real EX200, work through 16 task scenarios that integrate every domain, then unfold each task's solution commands and explanation to grade yourself. Sum the points against the 210/300 pass line and verify that your work survives a reboot.
AWS Certified CloudOps Engineer - Associate (SOA-C03) #11 Domain 4-2 Networking — Route 53,CloudFront,Delivery Operations
The eleventh post of the SOA-C03 series covers the second axis of the networking domain: DNS and content delivery. From an operations perspective, it organizes Route 53 record types and routing policies, health checks and failover, CloudFront caching and origin configuration, ACM certificates, and delivery troubleshooting such as caching and latency.
Certified Kubernetes Administrator (CKA) #26: Exam Tips, Time Management, and Patterns People Miss
A condensed cheat sheet to read one more time right before you sit the CKA hands-on exam. We pull together time management for running roughly 15–20 tasks in 2 hours, the priority order driven by points and troubleshooting, a refreshed kubectl speed setup, context switching across multiple clusters, using the official docs, the recurring patterns where operators bleed points and how to avoid them, easily confused concept pairs, and a pre-exam checklist for each of the five domains. Next up in #27 is a full-scale hands-on mock exam.
Certified Kubernetes Application Developer (CKAD) #21 Full-Length Practice Exam — 18 Tasks with Solutions
The final post of the Certified Kubernetes Application Developer (CKAD) series. Work through 18 task scenarios that integrate every domain in the same flow as the real exam, then unfold each task's solution commands, YAML, and explanation to grade yourself. Check your weak domains against the 66% pass line and lay out a review path.