rsync is a fast and versatile file synchronization tool that transfers only changed bytes, making it extremely efficient for incremental backups. Combined with cron or a systemd timer, it forms the basis of a reliable automated backup system on RHEL 9 without requiring additional backup software. The –link-dest option enables space-efficient dated snapshots that appear […]
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; […]
How to Configure GlusterFS Distributed Storage on RHEL 7 GlusterFS is a scalable, open-source distributed filesystem that aggregates storage from multiple servers into a single, unified namespace. It is commonly used for high-availability shared storage in environments without expensive SAN hardware. RHEL 7 can consume GlusterFS via the CentOS Storage SIG repository or the upstream […]
By default, the Docker daemon socket at /var/run/docker.sock is accessible only on the local host, but when you need to manage containers remotely — from a CI system, a monitoring server, or a developer workstation — you must expose the Docker API over TCP. Without TLS, any client with network access can control your Docker […]
Ansible playbooks are YAML files that describe the desired state of a set of managed servers using a series of tasks. Advanced playbook authoring goes beyond simple task lists to include: roles (reusable, shareable task bundles with a standard directory structure), handlers (tasks triggered only when a change occurs, such as restarting Nginx only when […]
Deploying an application to Kubernetes involves creating a set of resource objects that describe the desired state of the application — Kubernetes continuously works to make the actual state match this desired state. The core resources for most applications are: a Deployment (manages the desired number of running pod replicas and handles rolling updates), a […]
Kerberos is a network authentication protocol that uses symmetric-key cryptography and a trusted third party — the Key Distribution Center (KDC) — to authenticate users and services without transmitting passwords over the network. RHEL 9 ships the MIT Kerberos implementation and it integrates tightly with SSH, NFS, and other network services through GSSAPI. This tutorial […]
How to Install HashiCorp Vault for Secrets Management on RHEL 7 HashiCorp Vault is an open-source tool for securely storing and tightly controlling access to tokens, passwords, certificates, API keys, and other secrets throughout the software lifecycle. Unlike storing secrets in configuration files or environment variables, Vault provides a central, audited, and access-controlled secrets store […]
Buildah is a daemonless, rootless command-line tool for building OCI-compliant container images — without requiring a running Docker daemon or root privileges. On RHEL 9, Buildah ships as a first-class tool alongside Podman, and the two integrate tightly: images built with Buildah appear immediately in Podman’s local image store. Buildah’s fine-grained API lets you build […]
The sudo command allows permitted users to execute commands as root or another user without sharing the root password, making it the preferred mechanism for privilege escalation on RHEL 8. Properly configuring sudo is a foundational security task: it creates an auditable record of privileged actions and limits blast radius when accounts are compromised. This […]
