Linux Administration
Architecture, filesystem, users/groups, permissions, ACLs, processes, packages, SSH, systemd and journald.
Storage & Recovery
Filesystems, LVM, XFS, fstab failures, disk-full incidents, inode exhaustion and deleted-open files.
Boot & Kernel Recovery
Boot sequence, GRUB, emergency mode, initramfs, kernel troubleshooting and recovery methodology.
Networking & Infrastructure
IP, routing, DNS, DHCP, SSH, ports, NFS, PXE/Kickstart and multi-tier infrastructure.
Production Troubleshooting
CPU, memory, OOM, I/O wait, D-state, zombies, service failures and root-cause analysis.
Security, Automation & AI
SELinux, SSH hardening, firewall, Shell/Python automation and AI-assisted Linux health monitoring with Ollama/Qwen.