Filesystem

How to Set Up a Private Docker Registry on RHEL 9 — step-by-step RHEL 9 tutorial on Progressive Robot

How to Set Up a Private Docker Registry on RHEL 9

A private Docker registry allows organisations to store and distribute container images internally, without relying on Docker Hub or a cloud registry. This is essential for teams working with proprietary application images that cannot be stored in public registries, organisations with strict data sovereignty requirements, and environments with limited internet access. Docker provides an official […]

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How to Harden PHP 8.3: disable_functions, open_basedir, opcache on RHEL 9 — step-by-step RHEL 9 tutorial on Progressive Robot

How to Harden PHP 8.3: disable_functions, open_basedir, opcache on RHEL 9

PHP hardening reduces the attack surface of web applications by restricting what PHP scripts can do at the interpreter level. A default PHP installation exposes powerful functions that can be abused by attackers who exploit code injection vulnerabilities: system(), exec(), and passthru() allow execution of arbitrary OS commands; file_get_contents() with allow_url_fopen can fetch remote files; […]

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How to Install Apache HTTP Server on RHEL 9 — step-by-step RHEL 9 tutorial on Progressive Robot

How to Install Apache HTTP Server on RHEL 9

Apache HTTP Server (httpd) is the most historically significant web server in the history of the internet, powering billions of websites since 1995. On RHEL 9, Apache is available as httpd from the AppStream repository and integrates with SELinux, firewalld, and systemd. Apache’s module architecture makes it highly extensible: mod_rewrite for URL manipulation, mod_ssl for […]

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How to Monitor Disk Usage with df, du, lsblk and ncdu on RHEL 9 — step-by-step RHEL 9 tutorial on Progressive Robot

How to Monitor Disk Usage with df, du, lsblk and ncdu on RHEL 9

Running out of disk space is one of the most disruptive failures a server can experience. When a filesystem fills up, applications crash, log files stop writing (losing audit trails), databases corrupt transactions, and web servers return 500 errors. Proactive disk monitoring is essential — and RHEL 9 provides a full set of tools for […]

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How to Use rsync for Efficient File Synchronisation on RHEL 9 — step-by-step RHEL 9 tutorial on Progressive Robot

How to Use rsync for Efficient File Synchronisation on RHEL 9

rsync is the Swiss Army knife of file synchronisation for Linux administrators. Unlike scp, which blindly copies every file every time, rsync computes a rolling checksum to identify changed file blocks and transfers only what has changed — making subsequent syncs dramatically faster and less bandwidth-intensive. It preserves file attributes (permissions, ownership, timestamps, ACLs, extended […]

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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 Configure Log Rotation with logrotate on RHEL 9 — step-by-step RHEL 9 tutorial on Progressive Robot

How to Configure Log Rotation with logrotate on RHEL 9

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 […]

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