system administration – ITFROMZERO

VMware vSphere DirectPath I/O Configuration Guide: PCIe Device Passthrough for Virtual Machines

By IT From Zero October 6, 2026

DirectPath I/O grants virtual machines direct control over physical PCIe devices, eliminating virtualization overhead. Explore the mechanics, trade-offs, and practical setup on ESXi.

Network

How to Set Up an Internal Chrony NTP Server on Linux: Accurate and Secure for Production

By IT From Zero October 5, 2026

A hands-on guide to resolving distributed clock drift and setting up a secure, robust internal Chrony NTP server cluster on Linux.

Ubuntu

Snap Store Proxy: The Ultimate Bandwidth-Saving Hack for Managing Large Ubuntu Clusters

By IT From Zero September 11, 2026

Save 90% on internet bandwidth and manage Snap updates centrally with Snap Store Proxy. A detailed guide on installation and configuration for multi-server Ubuntu systems.

Monitoring

Installing Nagios Core on Ubuntu: Monitoring Rock-Solid Infrastructure with NRPE and Custom Plugins

By IT From Zero September 9, 2026

Don't overlook Nagios Core if you need absolute stability. A detailed guide on installing Nagios on Ubuntu, configuring NRPE, and writing high-quality custom monitoring plugins.

Centos

CentOS 7 End of Life: How to Revive Yum When the Official Mirrorlist Is Gone

By IT From Zero September 8, 2026

CentOS 7 has officially reached EOL, causing widespread Mirrorlist errors. Learn how to redirect your repos to the Vault archive to fix yum and keep your system running.

VMware

vCenter Frozen Due to Full /storage/db? A Definitive Guide for Sysadmins

By IT From Zero August 29, 2026

vCenter freezing with a 503 Service Unavailable error is often caused by a 100% full /storage/db partition. Here's how to safely expand disks and clean up the PostgreSQL DB.

VMware

Mastering vMotion on VMware ESXi: Don’t Let VM Migrations Crash Your Production Network

By IT From Zero August 24, 2026

Don't let vMotion crash your production network. A detailed guide on traffic isolation, Jumbo Frames configuration, and using PowerCLI to optimize VM migrations on VMware ESXi.

VMware

vCLS: The ‘Uninvited Guest’ on vSphere and a Management Survival Guide for Sysadmins

By IT From Zero August 23, 2026

Managing vSphere Cluster Services (vCLS) is no longer a headache. Learn how to move Agent VMs, use Retreat Mode, and troubleshoot Datastore issues on vSphere 7.0/8.0.

Centos

Storage Management on CentOS Stream 9 with Stratis: Stop Struggling with LVM

By IT From Zero August 16, 2026

Forget complex LVM commands. Learn how to use Stratis on CentOS Stream 9 to manage Storage Pools and Snapshots automatically, efficiently, and securely.

VMware

Mastering VMware Skyline Health: Proactive vSphere Diagnostics Before Issues Occur

By IT From Zero August 12, 2026

Stop reacting to vSphere crashes. Learn how to use VMware Skyline Health to automate hardware compatibility, driver, and system configuration checks like a pro.