Kernel Drivers

How to Set a Hostname and FQDN on RHEL 9 — step-by-step RHEL 9 tutorial on Progressive Robot

How to Set a Hostname and FQDN on RHEL 9

A server’s hostname is its identity on the network. The fully qualified domain name (FQDN) combines the short hostname with the DNS domain, forming an address like web01.example.com. Many services depend on a correctly configured hostname and FQDN to function properly: email servers use the FQDN in SMTP HELO greetings (incorrect values cause delivery rejections), […]

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How to Configure Automatic Security Updates on RHEL 9 — step-by-step RHEL 9 tutorial on Progressive Robot

How to Configure Automatic Security Updates on RHEL 9

Unpatched software is the leading cause of server compromise. The majority of publicly disclosed vulnerabilities already have patches available by the time attackers start actively exploiting them — the window between patch availability and active exploitation has shrunk from months to days. Manually patching servers is error-prone and inconsistent at scale. Automatic security updates ensure […]

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How to Create and Manage Swap Space on RHEL 9 — step-by-step RHEL 9 tutorial on Progressive Robot

How to Create and Manage Swap Space on RHEL 9

Swap space acts as overflow memory. When the physical RAM is full, the Linux kernel moves the least-recently-used memory pages to swap on disk, freeing physical RAM for active processes. Without swap, when RAM is exhausted the Out of Memory (OOM) killer terminates processes — often the largest one, which is frequently your database or […]

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How to Monitor System Resources with htop, top and vmstat on RHEL 9 — step-by-step RHEL 9 tutorial on Progressive Robot

How to Monitor System Resources with htop, top and vmstat on RHEL 9

Every Linux administrator needs a reliable toolkit for answering the question “why is this server slow?” The answer is almost always in one of four resources: CPU, memory, disk I/O, or network. RHEL 9 includes several powerful tools for diagnosing resource contention: top is included in every base installation and provides a real-time process table; […]

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