Red Hat
General Red Hat Enterprise Linux notes for commands, logs, systemd, networking, storage, CUPS, Veritas, tcpdump and troubleshooting.
Every page is written as a practical beginner-friendly guide.
Daily Commands
Useful commands for daily admin checks.
Logs
Journalctl, log files and error checking.
Systemd
Services, status, restart, enable and troubleshooting.
Networking
IP, routes, ports, DNS and connection checks.
Storage and LVM
Disks, partitions, LVM and filesystem checks.
Inodes
Inode usage, old file listing and safe housekeeping.
Mounting
Mounts, findmnt, fstab and troubleshooting.
Disk Expansion
General non-Veritas disk expansion notes.
Veritas Disk Expansion
Cluster/Veritas-aware disk expansion flow.
Veritas Cluster
Cluster checks and safe read-only commands.
Veritas Rlink in DCM Mode
Rlink DCM mode checks and escalation flow.
vras-vradmind Service
VVR/VRAS service checks and restart notes.
Swap Expansion
Swap checks and expansion notes.
Accounts and SSH Access
Users, SSH access, keys and login checks.
CUPS / Printing
Printer creation, deletion and troubleshooting.
Zombie Processes
What zombies are and how to investigate them.
tcpdump
Packet capture examples and safe usage.
Scripts
Script notes and admin automation reminders.
Troubleshooting
General troubleshooting cases and patterns.