Linux System Administration

Overview

I manage and optimize Linux systems from the kernel up, ensuring your servers are secure, performant, and reliable. Whether you’re running a handful of VPS instances or a large fleet of bare-metal servers, I bring deep expertise in both Red Hat and Debian ecosystems to keep your infrastructure running smoothly.

Red Hat Ecosystem

Best for: Enterprise environments, compliance-driven workloads, and organizations that need long-term stability with commercial support.

• RHEL, AlmaLinux & Rocky Linux — Installation, configuration, and lifecycle management
• DNF/YUM — Package management, repository configuration, and module streams
• SELinux — Policy design, troubleshooting, and enforcing-mode deployments
• firewalld & nftables — Zone-based firewall rules and advanced packet filtering
• NetworkManager & systemd-networkd — Bonding, bridging, VLANs, and routing
• Cockpit & Satellite — Web-based administration and centralized fleet management

Debian Ecosystem

Best for: Community-driven projects, web servers, containers, and teams that value flexibility and a vast package ecosystem.

• Debian & Ubuntu — LTS releases, point upgrades, and minimal installs
• APT — Package management, PPAs, pinning, and local mirrors
• AppArmor — Mandatory access control profiles for application sandboxing
• UFW & iptables/nftables — Simple and advanced firewall configurations
• Netplan & ifupdown — Declarative network configuration
• Landscape & Ansible — Centralized management and configuration automation

Security & Hardening

• Kernel hardening — sysctl tuning, module blacklisting, and secure boot
• SSH — Key-based auth, bastion hosts, and fail2ban integration
• Audit & compliance — CIS benchmarks, Lynis audits, and remediation scripts
• Intrusion detection — AIDE file integrity monitoring and log analysis
• Backup strategies — rsync, BorgBackup, and off-site replication

Networking

• Routing & NAT — Static routes, policy routing, and masquerading
• DNS — BIND, Unbound, and split-horizon configurations
• Load balancing — HAProxy and keepalived for high availability
• VPN — WireGuard, OpenVPN, and IPsec site-to-site tunnels
• Monitoring — Prometheus node exporter, netdata, and custom alerting

How I Work

1. Assessment — Audit existing systems, identify bottlenecks and security gaps
2. Planning — Define architecture, migration strategy, and rollback procedures
3. Implementation — Deploy changes with minimal downtime using blue-green or canary approaches
4. Documentation — Runbooks, network diagrams, and configuration inventories
5. Monitoring & maintenance — Proactive alerting, patch management, and capacity planning
6. Knowledge transfer — Training your team and leaving clear operational procedures

Technologies

Category	Tools
Red Hat	RHEL, AlmaLinux, Rocky, DNF, SELinux, firewalld, Cockpit, Satellite
Debian	Debian, Ubuntu, APT, AppArmor, UFW, Netplan, Landscape
Security	OpenSSH, fail2ban, AIDE, Lynis, CIS-CAT, WireGuard
Networking	HAProxy, keepalived, BIND, Unbound, nftables, iptables
Automation	Ansible, Bash, systemd, cron, Prometheus, netdata