CK notes - Field Notes of a 16-Year IT Systems Engineer

When production database or application servers running RHEL, Rocky Linux, CentOS (7 ~ 9), or Ubuntu (20.04 ~ 24.04 LTS) reach 90%+ disk utilization, scheduling emergency maintenance downtime is rarely an acceptable option. In modern virtualization (VMware, KVM, Nutanix, SimpliVity) and cloud infrastructures, performing 100% online, non-disruptive storage expansion is an essential skill for system engineers. Here is the battle-tested standard operating procedure for triggering a kernel SCSI bus rescan, extending LVM physical/logical volumes, and expanding filesystems (XFS vs EXT4) without unmounting. ...

After completing the deployment of an HPE SimpliVity 6.2.0 and VME (VM Essentials) cluster, the next operational milestone is provisioning workload virtual machines (VMs, Instances) and installing target guest operating systems (Linux, Windows Server). In VM Essentials, deploying virtual machines from scratch requires registering OS installation ISO media in the Virtual Image Library. To ensure high-capacity ISO files are stably retained and universally accessible across all cluster nodes, an NFS file share storage backend must be pre-integrated into VME Manager. ...

After initial deployment of an HPE SimpliVity HVM or VME (VM Essentials) cluster, only the default Management network is configured. Putting production workload virtual machines (VMs) into service requires adding dedicated data networks or tenant VLANs. The deployment workflow consists of two primary stages: creating a network bond interface at the physical host layer (via HPE VM Console TUI), and then mapping it as an Open vSwitch (OVS) network router within the VME Manager web console to attach to VMs. ...

Working with IT infrastructure systems for many years creates a habit of analyzing every decision—even personal vehicle choices—through the lens of cost-to-benefit ratios and risk management. Recently, as I began looking for a car to handle daily commuting and client visits, Hyundai’s hydrogen fuel cell vehicle, the NEXO, entered my shortlist. While the upcoming 2nd-generation The All-New NEXO—featuring bold boxy SUV styling and modern pixel lighting derived from the INITIUM concept—looks appealing, evaluating the purchase methods brings a classic dilemma: ...

Operating Cisco MDS SAN switches—the storage fabric backbone in enterprise datacenters—requires real-time telemetry into hardware component health (fans, power supplies, thermal sensors), FC port link state, and fabric zoning events via an integrated Network Management System (NMS: Zabbix, PRTG, Nagios). A frequent misconfiguration in production is executing snmp-server enable traps globally. Indiscriminately enabling every trap floods the monitoring collectors with low-severity debug notifications, triggering trap storms and elevating switch CPU utilization. ...

📌 Local LLM on My PC: Ollama Practical Series Part 1. What is Ollama, a Local AI Running Free on My PC? (Concepts & Features)> -Part 2. Windows 11 Ollama Installation & First Model Setup Guide> -[Current Post] Part 3. Ollama Practical Applications: Terminal Chat, WebUI, and REST API In Parts 1 and 2, we covered the architectural advantages of local LLMs in air-gapped environments and walked through installing Ollama on Windows 11 to run lightweight models in the terminal. ...

📌 Local LLM on My PC: Ollama Practical Series Part 1. What is Ollama, a Local AI Running Free on My PC? (Concepts & Features)> -[Current Post] Part 2. Windows 11 Ollama Installation & First Model Setup Guide> -Part 3. Ollama Practical Applications: Terminal Chat, WebUI, and REST API Following the foundational concepts discussed in Part 1 regarding why air-gapped environments benefit from local LLMs and why 2B–3B parameter models are best suited for standard business laptops, this guide walks through the hands-on deployment process. ...

📌 Local LLM on Personal Workstation: Practical Series Table of Contents [Current Post] Part 1. What is Ollama, a Local AI Running Free on Your PC? (Concepts & Features)> -Part 2. Windows 11 Ollama Installation & First Model Setup Guide> -Part 3. Practical Usage: From CLI Mastery to WebUI & API Integration Generative AI has become integral to software engineering workflows, but datacenter field operations present unique constraints. High-security enterprise environments—including financial transaction centers, defense installations, power plants, and public infrastructure—operate in air-gapped isolation with zero outbound internet connectivity. ...

It is never too late to start documenting everyday moments and vehicle upkeep. Today, I am logging the routine engine oil service for my car—a trusted companion that carries me across the country to client sites day in and day out. With frequent nationwide trips, keeping the car in top mechanical shape is essential. In the first half of this year alone, the car went through two oil changes as mileage accumulated rapidly. ...

With VMware’s recent licensing changes, many enterprise data centers are looking closely at lightweight, KVM-based virtualization alternatives. One viable enterprise solution is HPE SimpliVity 6.2.0 powered by HPE VM Essentials (VME). In my 16 years as an infrastructure engineer deploying servers and SAN fabrics, I have found that 90% of HCI deployment failures boil down to two things: sloppy physical/VLAN network segmentation andmisplaced quorum (Arbiter) architecture. This guide condenses the entire deployment lifecycle—from pre-flight network planning to management server staging, node initialization, and automated OVC provisioning via VME Manager—with battle-tested field troubleshooting insights. ...