RHEL family tutorials

Check, disable or set Transparent HugePages to madvise on RHEL 8–10, Rocky Linux, AlmaLinux, CentOS Stream and Oracle Linux.

Download and sync complete RPM repositories on RHEL 8/9/10, Rocky Linux, AlmaLinux, CentOS Stream, and Oracle Linux using dnf reposync, repository metadata, GPG verification, and offline clients.

Create Anaconda updates.img on RHEL 8–10, embed it in boot media with mkksiso, load it with inst.updates, and verify the installer overlay.

Configure Postfix as a null client or internal SMTP relay on RHEL 9 and 10, Rocky Linux, AlmaLinux, CentOS Stream, and Oracle Linux using relayhost, SASL authentication, STARTTLS, SWAKS, and queue troubleshooting.

Configure GNOME Remote Desktop with RDP on RHEL 10, Rocky Linux 10, AlmaLinux 10 and CentOS Stream 10 as the TigerVNC replacement.

Install and configure TigerVNC Server on RHEL 8 and 9, Rocky Linux, AlmaLinux, and CentOS Stream using user mappings, systemd, GNOME, firewalld, and secure VNC connections.

Configure local, remote and dynamic SSH port forwarding on RHEL 8–10, Rocky Linux, AlmaLinux, CentOS Stream and Oracle Linux.

Create a system-level systemd service that starts at boot and runs as a dedicated non-root user and group on Ubuntu, Debian, Fedora, RHEL, Rocky Linux, AlmaLinux, CentOS Stream and Oracle Linux.

Learn how to secure BIND primary-to-secondary DNS zone transfers with TSIG on RHEL, Rocky Linux, AlmaLinux, and CentOS Stream using HMAC-SHA256.

Learn how to restart the cron or crond service on Ubuntu, Debian, RHEL, Rocky Linux, AlmaLinux and CentOS, when a restart is required, and why crontab changes normally reload automatically.

Learn which command to use to restart, reload, or reconnect networking on RHEL, Rocky Linux, AlmaLinux, CentOS Stream, Oracle Linux, and Fedora—from nmcli reload to legacy network.service workflows.

Mount a local filesystem with a systemd mount unit on RHEL 8–10, Rocky Linux, AlmaLinux, CentOS Stream and Oracle Linux without editing fstab.

Compare the RHEL and Debian Linux families, including RPM vs DEB, DNF vs APT, repositories, release models, lifecycle, security, support, configuration, cloud images and server use cases.

Compare Rocky Linux, AlmaLinux and Red Hat Enterprise Linux by compatibility policy, governance, repositories, support, lifecycle, certifications, migration paths and production use cases.

Compare Fedora, CentOS Stream and Red Hat Enterprise Linux, including their development flow, release lifecycle, package freshness, stability, support, subscriptions, repositories and best use cases.

Learn how Unix, Linux, GNU/Linux and Linux distributions relate, why Ubuntu, Debian, Fedora, RHEL, Rocky Linux and Arch differ beyond desktop themes, and how to identify your distro from the shell.

Install Java on RHEL, Rocky Linux, AlmaLinux, CentOS Stream, Oracle Linux, or Fedora using OpenJDK, Eclipse Temurin, or Oracle JDK, then configure alternatives, JAVA_HOME, updates, verification, and uninstall.

Install JasperReports Server on RHEL, Rocky Linux, AlmaLinux, CentOS Stream, Oracle Linux, or Fedora using the evaluation binary installer with bundled components or a production WAR deployment on supported Tomcat and …

Install EPEL on RHEL 8–10, Rocky Linux, AlmaLinux, CentOS Stream and Oracle Linux. Enable CRB or PowerTools, verify EPEL and fix repository errors.

Learn how to safely remove old Linux kernels using DNF or YUM on RHEL, Rocky Linux, AlmaLinux, Fedora, CentOS Stream, and Oracle Linux while keeping the running kernel and a working fallback.

Use grubby on RHEL, Rocky Linux, AlmaLinux, CentOS Stream, Oracle Linux, and Fedora to check the running kernel, pick a persistent default, and verify the choice before reboot.

Compare DNF4 and DNF5 command differences, plugins, history syntax, and group handling, and learn what to change in scripts before your distribution moves to DNF5.

Download RPM packages with all dependencies using DNF on RHEL, Rocky Linux, AlmaLinux, Fedora, CentOS Stream, and Oracle Linux for offline installation.

Fix curl error 60 and similar HTTPS failures on Linux when corporate SSL inspection replaces public certificates with a private root CA trusted on Windows but missing from the Linux trust store.

Set up a practical Ansible Git and VS Code workflow on Rocky Linux—clone a repo, edit YAML safely, commit playbooks, ignore secrets and cache files, run ansible-playbook from the integrated terminal, lint with …

Pin amazon.aws 8.2.0, set EC2 values in vars/aws_lab.yml, and use amazon.aws.ec2_instance with vpc_subnet_id and security group IDs to launch, tag, start, stop, and terminate instances by ID or tag filter.

Use Ansible on Rocky Linux 10 to generate /etc/hosts from inventory and facts, create and extract archives, render system reports with Jinja2 templates, and fetch reports to the control node.

Use Ansible on Rocky Linux 10 to open firewalld services and ports with runtime and permanent rules, set SELinux mode and booleans, add file contexts with sefcontext, apply labels with restorecon, and verify both layers …

Build Rocky Linux 10 storage with Ansible in order—partition a safe target disk, create LVM volume groups and logical volumes, format XFS, mount persistently in /etc/fstab, verify with lsblk/findmnt, and extend volumes …

Use Ansible on Rocky Linux 10 to start and enable systemd units, reload the manager, change default targets, reboot safely, manage cron and at jobs, and verify state with service_facts.