HTTPS for a Domestic-Only Home Server — Let’s Encrypt DNS-01 + DuckDNS Wildcard
When inbound from abroad is blocked (country restriction / CGNAT) and port-80 HTTP-01 fails, use certbot DNS-01 with a DuckDNS TXT hook to obtain a wildcard ...
Blog
Welcome. This is the English section of the blog. Browse recent posts below, or use the sidebar to jump to a category.
Recent Posts
Fix Arista ZTP Error: cannot copy to startup-config when ZeroTouch is enabled
The cause of the ‘cannot copy to startup-config when ZeroTouch is enabled’ error and the repeating ZTP retry logs on a factory-default Arista switch, how to ...
Core Network Concepts for Switch Redundancy — VLAN, SVI, LACP, MLAG/VLT, VRRP/VIP, IPMI, PXE
The terms that show up when you make a switch pair redundant — VLAN/SVI (L2·L3), LACP/Port-Channel/MLAG·VLT (link & chassis redundancy), VRRP/VIP·FHRP (g...
Testing Arista Switch GBIC (SFP28) Modules — Diagnosing xcvr-unsupported
When a 25G link won’t come up, how do you test the switch’s GBIC modules and reach a conclusion? Cross-analyze Tx/Rx optical power and Bias Current, the errd...
Manually Editing netplan to Set IP/Gateway/DNS on a NIC When cloud-init Auto-Generates the Config
Confirm the interface name → disable cloud-init networking → write the netplan yaml → apply safely with netplan try. Includes three options for whether to de...
Linux Serial Terminal Programs — Install, Use, and Compare screen/minicom/picocom/tio
From install to exit shortcuts, pros and cons, and clean removal — comparing screen, minicom, picocom, and tio for USB-serial console access
Assign a Management IP to an Arista Switch and Access It via SSH
From first console login to Management1 IP assignment, VRF check, admin account creation, confirming SSH is enabled, saving config, and testing SSH access fr...
Verifying a 25G Network — Server-to-Arista-to-Server Link Compatibility Test
How to verify, step by step, link negotiation, transceiver detection, FEC mode match, error counters, and throughput/latency in a Server A 25G NIC ↔ Arista 2...
AWS Elastic Beanstalk vs ECS vs EKS — What, When, and How
Comparing the three services by abstraction level and responsibility boundary, where each sits between IaaS and PaaS, and the 7-step procedure for how a Pod ...
Netlify vs Vercel and the Static Hosting Landscape — What Are the Real Limits for Personal Users?
Netlify is limited and Vercel isn’t? — Let’s fix the terminology first, then map the real boundaries of the free tiers (build minutes, bandwidth, commercial ...
Migrating Docker Registry (registry:2) to Harbor with Near-Zero Downtime
Bring up Harbor on a temporary port first, move the images, then take over the original port in a short cutover — switching registry:2 to Harbor with no node...
Checking for Abnormal Pods in a Kubernetes Cluster
What the STATUS column really means, the field-selector pitfall, and how to tell whether Completed is normal — a practical reference for quickly isolating br...
A Practical Git History Rewrite Workflow (rebase · filter-branch · safe push)
The standard workflow for rewriting Git history: investigate → back up → interactive rebase (drop/reword) → resolve conflicts → filter-branch (author/date) →...
Multipass — The Easiest Way to Spin Up an Ubuntu VM in a Few Commands
Create an Ubuntu VM with a single multipass launch. From installation to resource options, cloud-init, and a libvirt/KVM comparison for dev and test environm...
Complete Guide to File Compression on Ubuntu — zip and tar (gzip/bzip2)
Use zip -r for multiple files and tar -czvf to bundle directories. Learn the difference between gzip and bzip2 with hands-on examples
agentmemory — Persistent Memory So Claude Code Remembers Your Work
Claude Code forgets everything when a session ends. agentmemory auto-records your work via hooks and re-injects it next session, eliminating re-explaining
Complete Guide to GitHub Multi-Account Setup — 4 Methods Compared
Separate author with includeIf, separate auth with SSH host aliases — and accounts switch automatically with cd. Four methods compared step by step
GitHub Actions Workflow Guide — Line-by-Line of deploy.yml and stale.yml
From a simple bot workflow (stale.yml) to a multi-job build/deploy workflow (deploy.yml) — learn the GitHub Actions execution model by line-by-line analysis ...
GitHub Multi-Account Switching — Using gh auth switch
One gh auth switch line changes who your git push goes as. Credential helper internals, PAT issuance, account switching, and real-world pitfalls in one guide
Checking RAID Environment Disks on Ubuntu — MegaRAID + smartctl Guide
The disk visible to the OS may be a Virtual Disk — use smartctl with the megaraid option to inspect Physical Disks behind the RAID Controller
Kubernetes Update Strategies — Rolling Update, Blue/Green, and Canary
K8s updates must be understood as two layers — API-level strategy (A) and deployment pattern (B). From Rolling/Blue-Green/Canary comparison to host-kernel-co...
Why Docker Chose OCI Artifacts for AI Model Packaging — ModelPack and the New Standard
Treating AI models like Docker — push/pull models from existing registries like Docker Hub and Harbor via OCI Artifacts, the new standard
Jekyll SEO Part 4 — Cleaning Up Search Console Issues (404, redirect, noindex)
SEO series Part 4. Diagnose remaining Search Console issues by four categories, then apply noindex meta automation in seo.html and trailing slash fixes in na...
Adding a Worker Node to an Existing Kubernetes Cluster with Kubespray
Inventory registration, SSH/sudo setup, scale.yml –limit execution, and solving the fact cache 404 error — a real-world walkthrough
Complete docker compose down — Cleaning Up Containers, Volumes, and Images
docker compose down alone leaves volumes and images behind — situational delete options and full reset methods
Installing a Specific Ubuntu Version on WSL (Windows 11)
Use wsl –install -d Ubuntu-22.04 to install the version you want, set the default distribution, with a Microsoft Store alternative
How to Remove WSL - From Deleting a Distribution to a Full Reset (Windows 11)
Use wsl –unregister to delete a distribution, wsl –uninstall to remove WSL entirely, or disable WSL from Windows Features
WSL Password Reset (Windows 11)
Log in as root with wsl -u root, then reset the password using passwd
SSD Secure Erase on Windows 11 — Unrecoverable Deletion
Regular formatting leaves SSD data recoverable — compare Secure Erase, Rufus+ISO, and DiskPart clean all
OCI Registry and Harbor — Container Image Management (K8s & OpenStack)
Harbor is an Enterprise-grade Private OCI Registry — a standard repository for pushing/pulling container images in Kubernetes and OpenStack