Linux

Production PostgreSQL performance tuning on Linux: kernel, I O, WAL, autovacuum, PgBouncer, monitoring, and benchmarking for high concurrency systems.

Hands-on Linux guide to build, validate, and debug complex nftables firewall rules, covering stateful filtering, NAT, sets, atomic updates, and production tuning.

Step by step Linux guide to tune systemd journald for high volume servers: storage, rate limits, compression, rotation, remote forwarding, monitoring, and troubleshooting.

Practical Linux TCP tuning for high throughput servers: sysctl tweaks, autotuning, congestion control, NIC offloads, iperf3 testing, and safe rollback steps.

Enterprise focused, step by step guide to harden SSH on Linux servers: key based auth, sshd_config lockdown, rate limiting, 2FA, chroot SFTP, and audit logging.

Hands on guide for sysadmins to automate DKMS kernel module deployment on Linux: systemd load ordering, Secure Boot signing, CI packaging for deb and rpm, and troubleshooting.

Step by step Linux guide to deploy an SSH certificate authority: create CA keys, sign host and user certs, enforce short lived certs, automate, rotate, and revoke.

Hands on Linux guide to deploy, build, apply, and automate kpatch live kernel patching on RHEL CentOS Fedora with monitoring and rollback tips.

Practical, step by step guide to diagnose and fix Linux OOM killer events on production servers: read logs, adjust oom_score_adj, use cgroups, tune overcommit and swap.

Step by step Linux troubleshooting for high I/O wait and disk latency using iostat, atop, blktrace, perf, fio and kernel tunables to find and fix bottlenecks.