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1,794 practical guides for cPanel, Plesk and DirectAdmin, Linux and Windows servers, websites, databases, DNS and security, from your first login to troubleshooting.
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How to fix a 400 Bad Request error
A 400 Bad Request error means the server could not understand the request. Learn the common causes, from bad URLs to oversized cookies, and how to fix each one.
Fix PHP session errors: save path, permissions and lost logins
Fix session_start() errors and users being logged out: session.save_path permissions, full disks, garbage collection, cookie settings, multiple servers and Redis sessions.
Fix PHP cURL error 28 and other outgoing request errors
Fix cURL error 28 (operation timed out), error 6 (could not resolve host) and error 7 (failed to connect) when PHP, WordPress or Laravel call external APIs.
Fix common Laravel errors after deployment
Fix the Laravel errors that appear most after deploying: 500 with no message, 419 Page Expired, No application encryption key, storage permissions, cached config and missing vendor.
Catch-all email addresses: pros, cons and safer alternatives
What a catch-all (default address) does, why it attracts spam and dictionary attacks, how to set or disable it in cPanel and Postfix, and better alternatives like aliases and plus addressing.
Fix "Cannot modify header information - headers already sent"
Fix the PHP warning 'headers already sent by output started at file:line': stray whitespace, BOM characters, echo before redirects, closing tags and plugin output.
Fix common Composer errors on a server
Solve frequent Composer problems: memory exhausted, PHP version or extension requirements, dependency conflicts, lock file mismatches, authentication and running as root.
Why forwarded email fails SPF and DMARC: SRS and ARC explained
Why forwarding breaks SPF and sometimes DKIM, how Sender Rewriting Scheme (SRS) and ARC fix it, how to enable SRS on cPanel and Postfix, and safer alternatives to forwarding.
Debug a blank white page in PHP (display and log errors)
Turn a blank PHP page into a readable error: enable error logging safely, find the right log file on cPanel or a VPS, and fix the usual causes like syntax errors and missing extensions.
Stop outgoing spam from your mail server with rate limits
How hacked mailboxes and scripts send spam from servers, how to detect it in logs and queues, and how to limit outgoing mail per user and per domain on Postfix, Exim and cPanel.
Fix "Allowed memory size exhausted" PHP errors
Understand the PHP fatal error 'Allowed memory size of X bytes exhausted', raise memory_limit on cPanel or a VPS, and find the code that uses too much memory.
Point a domain to your hosting: nameservers vs A record
Two ways to point a domain to MdmHost hosting: change nameservers or keep your DNS and edit A, CNAME and MX records. When to use each, step by step, and how to check it worked.
Convert SSL certificate formats: PEM, CRT, DER, PFX and P7B with OpenSSL
What the common SSL certificate file formats are, how to tell them apart, and the exact OpenSSL commands to convert between PEM, DER, PFX/PKCS#12 and P7B for cPanel, Windows and other servers.
Restore DNS zones, cron jobs, SSL certificates and FTP accounts with JetBackup 5
How to restore individual DNS zones, cron jobs, SSL certificates and FTP accounts from JetBackup 5 in cPanel without overwriting your files, databases or email.
DNS server software: BIND vs PowerDNS explained
Authoritative vs recursive DNS servers, how BIND and PowerDNS differ in storage, performance and features, what cPanel uses, and how to test a DNS server with dig.
Install a hosting control panel on a Virtualizor VPS
Choose between cPanel, Plesk, DirectAdmin and free panels for your VPS, use Virtualizor's control panel installer where offered, or install manually on a clean OS.
Customer cancelling? Give them their data and close the account properly
A clean cancellation process for reseller customers: provide a full cPanel backup, help with domain and email moves, suspend, then terminate after a grace period.
Switch from CSF to the Imunify360 firewall (root guide)
Move a cPanel server from CSF/LFD to the Imunify360 firewall as root: plan the switch, migrate allow and deny lists, open the right ports and verify nothing is locked out.
Install and configure MySQL Governor on CloudLinux (root guide)
Install CloudLinux MySQL Governor on a cPanel server as root, choose the right database version, set the mode and per-user limits, and monitor restricted users with dbtop.
Imunify360 found a phishing page in my account: what to do
What to do when Imunify360 detects a phishing kit or fake login page in your hosting account: remove it, find how it got in, secure the account and handle blacklists.
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- Getting startedYour first hour with a new server: access, logins and basics.83 guides
- cPanelFiles, databases, email, domains and every cPanel tool, step by step.67 guides
- WHM & resellingWHM, packages, reseller accounts, WHMReseller and running a hosting brand.53 guides
- WordPressInstall, secure, speed up, migrate and fix WordPress sites.49 guides
- Email & webmailMailboxes, webmail, forwarders, spam filters and email delivery.67 guides
- DomainsRegistering, transferring and managing domains and nameservers.27 guides
- SSL certificatesFree AutoSSL, Let's Encrypt, paid certificates and HTTPS.41 guides
- CloudLinuxCloudLinux setup and use: LVE limits, CloudLinux Manager, CageFS and PHP/Node.js selectors.31 guides
- LiteSpeedLiteSpeed Web Server, LSCache and the LiteSpeed Cache plugin: install, settings and tuning.35 guides
- Imunify360Malware scanning, firewall and proactive defence with Imunify360.24 guides
- SoftaculousInstall, update, clone and back up apps with Softaculous.24 guides
- WP SquaredcPanel's WordPress platform: sites, plugins, staging and backups.9 guides
- SitePadBuild and publish websites with the SitePad builder.9 guides
- SitejetDesign, edit and publish sites with the Sitejet builder.9 guides
- WHMResellerAlpha and master resellers with WHMReseller: install, setup and use.12 guides
- VirtFusionInstall, set up and manage VirtFusion: hypervisors, packages, servers and WHMCS integration.28 guides
- VirtualizorManage your VPS with Virtualizor: power, OS reinstall, VNC, IPs and backups.44 guides
- PleskWebsites, email, databases and settings in the Plesk panel.53 guides
- DirectAdminUsers, domains, email and reseller tools in DirectAdmin.41 guides
- WHMCSBilling, automation, products and client management with WHMCS.52 guides
- Control panelscPanel & WHM, Plesk, DirectAdmin and other panels on your VPS.107 guides
- SecurityKeys, passwords, firewalls and keeping a server patched.138 guides
- Networking & DNSIP addresses, reverse DNS, ports and traffic.72 guides
- Websites & appsWeb servers, WordPress, PHP, Node.js, SSL and app hosting.83 guides
- DatabasesMySQL, MariaDB, PostgreSQL, Redis and MongoDB on a VPS.80 guides
- Billing & accountInvoices, renewals, the client area and your account.9 guides
- TroubleshootingWhen something is not working: checks and fixes.127 guides
- Linux VPSSSH, packages, services and everyday Linux administration.265 guides
- Windows VPS & RDPRemote Desktop, Windows Server settings and Admin RDP tips.73 guides
- Docker & DevOpsContainers, Git deploys, automation, monitoring and backups.82 guides
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