The Linux kernel exposes hundreds of tunable parameters through the sysctl interface that control network behavior, memory protection, and file system security. Many of these defaults prioritize compatibility over security. By writing a hardening configuration to /etc/sysctl.d/, you can reduce the kernel attack surface, enable mitigations against common network attacks, and enforce memory safety features […]
🟡 Medium ⏱ 5–30 min Last verified: 18 June 2024 📖 ~1 min read Table of contents Symptom & Impact Environment & Reproduction Root Cause Analysis Quick Triage Step-by-Step Diagnosis Solution – Primary Fix Solution – Alternative Approaches Verification & Acceptance Criteria Rollback Plan Prevention & Hardening Related Errors & Cross-Refs References & Further […]
ClamAV is an open-source antivirus engine widely used on Linux servers to detect malware in files destined for Windows users — such as email attachments, uploaded documents, and shared network storage. While Linux systems are largely immune to the Windows malware that ClamAV detects, running it is a responsible practice wherever Linux servers act as […]
Log files are the primary diagnostic tool for server administrators — but without rotation they become a problem in their own right. An unrotated /var/log/nginx/access.log on a busy server can grow to tens of gigabytes within weeks, filling the filesystem, crashing the logging application, and making the log itself unusable because no tool can efficiently […]
iptables has been the standard Linux packet-filtering firewall for over two decades, and while RHEL 9 ships with nftables and firewalld as the preferred tools, iptables remains available and is widely understood by seasoned administrators. Learning iptables gives you deep insight into how Linux netfilter works and is valuable for managing legacy systems or containers […]
Graylog is an open-source centralised log management platform that collects, indexes, and analyses log data from across your infrastructure in one place. On RHEL 9, deploying Graylog 5.x gives operations teams powerful search, alerting, and dashboarding capabilities without relying on cloud-based log services. Graylog depends on MongoDB for metadata storage and OpenSearch (or Elasticsearch) for […]
cAdvisor (Container Advisor) is an open-source daemon from Google that collects, aggregates, and exposes resource usage and performance metrics for every running container on a host. Unlike Docker’s built-in docker stats, cAdvisor exposes its data in Prometheus format, making it a natural fit for scraping alongside Node Exporter. This tutorial covers running cAdvisor on RHEL […]
Introduction FreeBSD 14 is a UNIX-derived operating system renowned for its network stack performance, ZFS integration, and Jail isolation primitives. Setting up set up carp high availability on freebsd 14 on FreeBSD 14 follows the rc.conf/service(8) paradigm rather than systemd, which means enabling a service and configuring its startup options are done differently from any […]
Introduction This guide explains how to Install Perl on FreeBSD 14 on FreeBSD 14. FreeBSD uses the pkg(8) binary package manager, rc.conf(5) for service startup configuration, and pf(4) as its primary packet filter. There is no SELinux or AppArmor — instead, FreeBSD provides the MAC (Mandatory Access Control) framework and Capsicum for fine-grained privilege separation. […]
Introduction This guide explains how to Configure Swap Space on FreeBSD 14 on FreeBSD 14. FreeBSD uses the pkg(8) binary package manager, rc.conf(5) for service startup configuration, and pf(4) as its primary packet filter. There is no SELinux or AppArmor — instead, FreeBSD provides the MAC (Mandatory Access Control) framework and Capsicum for fine-grained privilege […]
