Memcached is a high-performance, distributed in-memory key-value cache designed specifically for caching database query results, session data, and computed values. Unlike Redis, Memcached is deliberately simple — it does not support persistence, replication, or complex data types. This simplicity makes Memcached extremely fast and memory-efficient: it uses a slab allocator to eliminate memory fragmentation and […]
Suricata is a high-performance, open-source network intrusion detection and prevention system (IDS/IPS) that inspects traffic in real time against a rule set to identify threats, policy violations, and malicious activity. On RHEL 9, Suricata integrates cleanly with systemd and can run in passive IDS mode (logging alerts without blocking) or active IPS mode (dropping malicious […]
ZFS (Zettabyte File System) delivers enterprise-grade data integrity features including checksumming, copy-on-write snapshots, built-in RAID, and efficient replication — without requiring a separate volume manager. Although ZFS is not included in RHEL 9’s default kernel, the OpenZFS project provides DKMS-based packages that work reliably on RHEL 9. This tutorial covers installing OpenZFS, creating pools and […]
nftables is the modern successor to iptables and is the default firewall framework in RHEL 9. It replaces iptables, ip6tables, arptables, and ebtables with a single unified tool, offering better performance through an improved kernel path, atomic rule replacement, and a cleaner, more readable configuration syntax. This tutorial covers everything you need to know to […]
SNMP (Simple Network Management Protocol) remains a widely used protocol for monitoring network devices, servers, and applications in enterprise environments. While SNMPv1 and SNMPv2c rely on unencrypted community strings, SNMPv3 introduces authentication and encryption, making it suitable for security-conscious deployments. This tutorial covers installing and configuring net-snmp on RHEL 9 with SNMPv3, extending the agent […]
Efficient Docker image and container management is fundamental to maintaining a healthy container environment. Docker images accumulate on hosts — old base images, build cache layers, and unused intermediate images can consume tens of gigabytes of disk space if not managed regularly. Understanding the Docker image layer model is key: images consist of read-only layers […]
IPsec VPNs provide strong, standards-based encryption and are natively supported by Windows, macOS, and iOS without additional client software. StrongSwan is a full-featured IKEv2/IPsec implementation that runs well on RHEL 9. This tutorial walks you through installing StrongSwan, generating a PKI certificate chain, and configuring an IKEv2 VPN server that accepts connections from native OS […]
Percona XtraBackup is the industry-standard open-source tool for online, non-blocking hot backups of MySQL and MariaDB InnoDB databases. Unlike mysqldump, which produces a logical SQL dump and requires more time for large databases, XtraBackup performs a physical backup — copying InnoDB data files directly while MySQL is running, without acquiring table locks that would block […]
SQLite is a self-contained, serverless, zero-configuration SQL database engine that stores an entire database in a single file on disk. Unlike MySQL, PostgreSQL, and MongoDB which require a running server process, SQLite is a library that is linked directly into the application — there is no network connection, no authentication, and no administration overhead. SQLite […]
PostgreSQL provides two complementary backup tools: pg_dump for logical backups of individual databases (SQL statements that can be restored to any PostgreSQL version) and pg_basebackup for physical backups of the entire database cluster (exact byte-for-byte copy of the data directory, used for streaming replication setup and point-in-time recovery). pg_dump is the right tool for most […]
