Deepak Prasad

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.

Compare rolling-release and fixed-release Linux distributions by package freshness, stability, update frequency, upgrade risk, maintenance effort, support lifecycle and desktop or server use cases.

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 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.

Compare RPM and DEB Linux packages, including package structure, metadata, dependencies, scripts, signatures, installation commands, querying, repositories, conversion risks and supported distributions.

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 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.

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.

Free Kubernetes tutorial that takes you from cluster install to CKA/CKAD-level topics - pods, deployments, RBAC, networking, Helm, security, autoscaling. 59 hands-on lessons across 11 chapters, every example tested on …

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.

Use Ansible on Rocky Linux 10 to create users and groups with UID/GID, manage SSH authorized keys, generate SSH keys, set account expiry, store password hashes with Vault, and configure validated sudoers files safely.

Learn Ansible dnf and yum_repository on Rocky Linux 10—install, remove, update packages, package groups, custom repo files, GPG check, enable or disable repos, and verification with tested playbooks.

Fix Ansible collection not found, module not found, FQCN resolution, collection path mismatches, and undefined variable errors in inventory, roles, and templates—with commands and real error output.

Debug Ansible playbooks by printing variables with debug, capturing task output with register, validating assumptions with assert, inspecting files and facts, and previewing changes with --check, --diff, and verbosity.