Infrastructure, Systems, and Connectivity
How Your Server Manages Domains, Virtual Hosts, Server Type Detection, Interface Locks, and WHM Keyboard Shortcuts
This article explains how overselling works for WHM resellers and how cPanel & WHM versioning, release tiers, and lifecycle management operate. It covers reseller resource limits, overselling behavior, version number structure, LTS policies, release tiers, and the production release workflow.
This article explains how service subdomains in cPanel & WHM use the cPanel service SSL certificate and how administrators can bypass this behavior if needed. It also describes the user experience when a Subaccount is invited to set its initial password through the User Manager interface.
This article explains how TailWatch monitors system logs in cPanel & WHM, how the chkservd driver checks and restarts services, how to add new monitored services, how to resolve common chkservd errors, and how other TailWatch drivers operate. It also covers process control, custom driver creation, and TailWatch management.
This article explains the locations and purposes of key log files used by cPanel & WHM, Webmail, and MySQL. It includes examples of log entries, details about user‑level DAV logs, system access logs, and service‑related logs. These logs help administrators troubleshoot authentication issues, service failures, and general system activity.
This article provides a detailed overview of the service daemons that operate within cPanel & WHM. These background processes power essential server functions such as email delivery, DNS management, PHP-FPM acceleration, brute force protection, log processing, Greylisting, Cron tasks, and more. The article also explains which daemons are affected by server profiles and how each service contributes to system performance and stability.
This article explains the update configuration files used by cPanel & WHM, including cpupdate.conf, which controls how the system updates cPanel, OS packages, and SpamAssassin rules; the noquotafs file, which excludes specific filesystem types from quota management; and the Third‑Party Applications Updates section, which lists bundled external applications across different cPanel versions.
This article provides a complete and structured explanation of the /var/cpanel/cpanel.config file, the core configuration file that stores nearly all Tweak Settings options in cPanel & WHM. It explains how the file works, how dynamic values behave, how caching is handled, and includes a categorized list of the most important keys with their descriptions, default values, and related WHM interface locations.
This article explains Upgrade Blockers in cPanel & WHM—issues that prevent the system from installing or upgrading to a newer version. It covers standard checks, version‑specific blockers, multi‑stage upgrade behavior, required pre‑upgrade conditions, and solutions for the most common blockers across versions 110 to 130.
How to Resolve CIFS Backup Permission Errors and Remote Transport Issues in cPanel & WHM
This article explains how cPanel & WHM automatically replaces weak, expiring, invalid, or revoked SSL certificates with free Let’s Encrypt certificates. It covers replacement conditions, the automated process, examples, how to disable automatic replacement, certificate management options, and troubleshooting issues such as CAA restrictions and missing FQDN hostnames.
This article explains how DNS caching works, why clearing your DNS cache may be necessary, and how to clear it on Windows, macOS, ChromeOS, Ubuntu, and other Linux systems. It also provides a complete step-by-step guide to configuring Reverse DNS (PTR records) in WHM, including system requirements, creating reverse DNS zones, editing PTR records, and testing your configuration.
