sysadmin Archives - Page 4 of 23 - ITFROMZERO

Virtualization tutorial - IT technology blog

Configuring Open vSwitch on Proxmox VE: Bridges, Bonds, and GRE Tunnels

By IT From Zero October 17, 2026

Troubleshoot Proxmox VE networking with Open vSwitch: quickly deploy emergency OVS Bridges, aggregate fault-tolerant 10GbE links with LACP Bonds, and connect cross-node VMs via GRE Tunnels.

Linux

A Guide to ncdu and duf on Linux: Visual Disk Usage Analysis and Cleanup from the Command Line

By IT From Zero October 16, 2026

Replace legacy df and du tools with ncdu and duf on Linux. Learn how to pinpoint storage hogs, resolve deleted open file locks, and clean up server disks safely.

Fedora

Guide to systemd-cryptenroll and YubiKey on Fedora: Unlock LUKS2 with FIDO2

By IT From Zero October 15, 2026

Configure systemd-cryptenroll with a FIDO2 YubiKey on Fedora to unlock LUKS2 with a single touch, maintain a secure fallback, and resolve Dracut boot issues.

Ubuntu

How to Install and Configure ClamAV on Ubuntu Server: Automated Database Updates and Scheduled Malware Scans

By IT From Zero October 15, 2026

Detailed guide on installing ClamAV on Ubuntu Server, troubleshooting freshclam lock errors, scheduling automated webshell quarantine cron jobs, and optimizing RAM to avoid the OOM Killer.

VMware

How to Use the vmkfstools Command on VMware ESXi: Managing, Cloning, and Converting VMDKs from the CLI

By IT From Zero October 14, 2026

A hands-on guide to using vmkfstools on VMware ESXi: how to convert Thick disks to Thin to reclaim space, expand virtual drives, and recover broken descriptor files via SSH.

Linux

Linux ZRAM Guide: Optimize Memory and Speed Up Your System with Compressed Swap

By IT From Zero October 13, 2026

ZRAM sets up a compressed swap partition directly in physical memory, helping Linux servers relieve memory exhaustion and fend off the OOM Killer without disk I/O bottlenecks.

Centos

Comprehensive Guide to Installing and Configuring Wazuh SIEM on CentOS Stream 9

By IT From Zero October 12, 2026

Battle-tested guide to deploying Wazuh SIEM on CentOS Stream 9: from a 5-minute all-in-one setup and firewalld rules to FIM alerts and automatic SSH brute-force IP blocking.

Network

Configuring Macvlan and IPVlan for Docker on Linux: Direct LAN IP Assignment and NAT Bypass

By IT From Zero October 12, 2026

Assigning physical LAN IPs directly to Docker containers completely bypasses conntrack NAT and lowers CPU overhead for VoIP/RTSP. A detailed guide to configuring Macvlan, IPVlan L2, and fixing host-to-container connectivity.

Fedora

Installing Grafana Loki and Promtail on Fedora Server: Centralized Logging, Way Lighter than ELK

By IT From Zero October 11, 2026

A hands-on production guide to deploying Grafana Loki and Promtail on Fedora Server for centralized logging. Highly resource-efficient compared to ELK, using under 400MB of RAM.

Ubuntu

Ubuntu Server Security Auditing with Lynis: Vulnerability Scanning and Practical Hardening

By IT From Zero October 10, 2026

A hands-on guide to installing Lynis on Ubuntu Server, analyzing Hardening Index reports, fixing common security flaws, and automating audits via cron.