RHEL 7

How to Configure Database Connection Pooling with PgBouncer on RHEL 7 — step-by-step RHEL 7 tutorial on Progressive Robot

How to Configure Database Connection Pooling with PgBouncer on RHEL 7

How to Configure Database Connection Pooling with PgBouncer on RHEL 7 Every PostgreSQL client connection spawns a backend process on the server, consuming approximately 5–10 MB of RAM for its working memory and adding overhead to the process scheduler. Applications that open hundreds of short-lived connections — such as PHP scripts, Node.js workers, or microservices […]

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How to Use Docker Volumes and Bind Mounts on RHEL 7 — step-by-step RHEL 7 tutorial on Progressive Robot

How to Use Docker Volumes and Bind Mounts on RHEL 7

How to Use Docker Volumes and Bind Mounts on RHEL 7 Containers are ephemeral by design — when a container is removed, any data written inside its writable layer is lost. Docker solves this with three types of persistent storage: named volumes, bind mounts, and tmpfs mounts. Named volumes are managed entirely by Docker and […]

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How to Tune Linux Kernel Parameters with sysctl on RHEL 7 — step-by-step RHEL 7 tutorial on Progressive Robot

How to Tune Linux Kernel Parameters with sysctl on RHEL 7

How to Tune Linux Kernel Parameters with sysctl on RHEL 7 The Linux kernel exposes hundreds of tunable parameters through the sysctl interface, allowing system administrators to adjust network behavior, memory management, file descriptor limits, and security policies without recompiling the kernel or rebooting. On Red Hat Enterprise Linux 7, these parameters are managed through […]

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Common Problems 115534

logrotate Not Rotating Large Logs

🟡 Medium   ⏱ 5–30 min  Last verified: 18 November 2021 📖 ~1 min read Table of contents Symptom & Impact Environment & Reproduction Root Cause Analysis Quick Triage Step-by-Step Diagnosis Solution – Primary Fix Solution – Alternative Approaches Verification & Acceptance Criteria Rollback Plan Prevention & Hardening Related Errors & Cross-Refs References & Further […]

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How to Back Up PostgreSQL with pg_dump and pg_basebackup on RHEL 7 — step-by-step RHEL 7 tutorial on Progressive Robot

How to Back Up PostgreSQL with pg_dump and pg_basebackup on RHEL 7

How to Back Up PostgreSQL with pg_dump and pg_basebackup on RHEL 7 A reliable backup strategy is one of the most critical operational requirements for any PostgreSQL deployment. On RHEL 7, PostgreSQL provides several complementary backup tools suited to different recovery scenarios: pg_dump for logical, per-database backups that can be restored selectively; pg_dumpall for capturing […]

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How to Set Up Pacemaker and Corosync for High Availability on RHEL 7 — step-by-step RHEL 7 tutorial on Progressive Robot

How to Set Up Pacemaker and Corosync for High Availability on RHEL 7

How to Set Up Pacemaker and Corosync for High Availability on RHEL 7 High availability (HA) clustering prevents individual server failures from causing service outages by automatically detecting node failures and restarting workloads on surviving nodes. On RHEL 7, the standard HA stack is built from three components: Corosync, which provides reliable cluster messaging and […]

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How to Install and Configure vim and nano on RHEL 7 — step-by-step RHEL 7 tutorial on Progressive Robot

How to Install and Configure vim and nano on RHEL 7

How to Install and Configure vim and nano on RHEL 7 Every Linux system administrator spends a significant portion of their time editing configuration files, scripts, and documentation directly on the server. RHEL 7 includes the minimal vi editor by default, but the full-featured vim and the beginner-friendly nano are far more practical for daily […]

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How to Build Grafana Dashboards for Linux Server Metrics on RHEL 7 — step-by-step RHEL 7 tutorial on Progressive Robot

How to Build Grafana Dashboards for Linux Server Metrics on RHEL 7

How to Build Grafana Dashboards for Linux Server Metrics on RHEL 7 Grafana is the de facto standard for visualising time-series data collected by Prometheus, InfluxDB, Graphite, and dozens of other data sources. A well-constructed Grafana dashboard can surface CPU saturation, memory pressure, disk I/O bottlenecks, and network anomalies at a glance, dramatically reducing the […]

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How to Harden SSH on RHEL 7 — step-by-step RHEL 7 tutorial on Progressive Robot

How to Harden SSH on RHEL 7

How to Harden SSH on RHEL 7 SSH (Secure Shell) is the primary remote administration protocol for RHEL 7 servers, and by default its configuration leaves several attack vectors open. Brute-force attacks against exposed SSH ports are constant on any internet-facing host, making SSH hardening one of the first tasks every RHEL 7 administrator should […]

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Common Problems 115634

Application port blocked by firewalld – RHEL 7 Post 007

🟡 Medium   ⏱ 5–30 min  Last verified: 25 October 2021 📖 ~1 min read Table of contents Symptom & Impact Environment & Reproduction Root Cause Analysis Quick Triage Step-by-Step Diagnosis Solution – Primary Fix Solution – Alternative Approaches Verification & Acceptance Criteria Rollback Plan Prevention & Hardening Related Errors & Cross-Refs References & Further […]

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