This site has been designed to be used as a reference point, with useful commands, installation and configuration guides.
You can simply use ctrl + f to search for a topic in this wiki.

• Troubleshooting
  • System
    • System Usage Summary
    • Process Investigation
    • Top 5 CPU Processes
    • Ram Usage Breakdown
    • Memory Hoggers
    • TCPDUMP
  • Web server
    • Apache Buddy
    • Apache Max Clients
    • php-fpm Investigating
      • php-fpm pal
      • fpm strace
    • Netstat
    • Connections to port
    • 'Site-down' Investigation
      • Log Summary
    • nginx server blocks (httpd -S equivalent)
    • HTTP Headers
  • mysql
    • mysql tuner
    • Process Investigation
    • mysql Engines
    • mysql slow logs
    • mysql Replication Investigation
    • mysql database size
  • Networking
    • NAT to public
    • Transmit/Receive Issues
    • vnstat
  • Other
    • Recap/rs-sysmon one-liner
    • How may cores?
    • List all crons
    • Largest files
    • Real Users
    • Brute-force?
    • uptime

* Bash
* Zed Editor
*Editor Environment Settings

• CentOS vs RHEL
• PHP Versions and Support

* Tutorials and config guides

• Apache
  
  • Installation
  • vhost
  • prefork
  • SSL
    • Convert .pfx to .pem
    • SSL Expiry
    • SSL Encryption Type
    • Poodle Fix
    • SSL Cipher/Protocol Check
  • Configuration
  • ** Modules **
    • Slow-loris Attack/Mod_reqtimeout
  • x-Forwarded-For
  • HTTP Authentication
  • .htaccess
  • Security
• Mysql
  • Install
  • my.cnf
  • Tuning
  • Users:
    • Creating/Dropping Users
    • Updating Users Password
    • Resetting lost root password
    • Granting Permissions
    • Changing Host
  • Databases
    • DB Management
  • Tables
    • Creating/Dropping
  • Show Process List
  • Slow Query Log
  • mysqldump
  • Holland Backup
  • phpMyadmin
  • Remote db Access
  • database/tables sizes
  • mysql replication (master slave)
• Networking
  • Adding Static Routes
• Logging
  • Recap
  • Sar
  • Logrotate
  • lsof
• PHP
  
  • php-fpm
  • Versions
  • info.php
  • php.ini
  • Securing PHP
  • Error Logging
  • php upgrade (yum-plugin-replace)
• iptables
  • Add Port
  • Deleting a rule
  • UFW
• Nginx
  
  • install
  • server block
  • Http Authentication
  • compression
  • Proxy Pass
  • rewrite/redirect code
  • SSL
  • Security
• Syncing/Replication/lsync
  • lsync
• Admin
  • Kernel
  • Tune2fs
  • Secure Copy (SCP)
  • find command
  • tar
  • awk + sed
  • rsync
  • Screen Sessions
    • Screen Share
  • rename
  • Sort
  • History TimeStamps
  • zip
• FTP/sFTP
  • vsFTPd
  • sFTP
• Mail
  • Sending Mail
• Cron Jobs
  • Format + Examples
• Varnish
  
  • install
  • configure
  • default.vcl
  • restart/test config
  • apache
  • nginx
• Fail2Ban
  • Install
  • Commands
  • SSH Configuration
  • xmlrpc
  • wp-login
• Memcached
  
  • install
  • troubleshoot
  • configure
• Redis
  
  • Clearing Cache
• Hardware
  
  • RAID
• Plesk
  • Admin password
  • mysql log in
  • General Plesk Stuff
  • Plesk Logs
  • Plesk FTP Details
• git
  • Installing
  • Cloning
  • Setting up a git
• Package Management
  • Yum
  • RPM
  • Repositories
  • yum replace
• SSH
  • Creating ssh Keys
    • And logging in with ssh key
  • ssh no-keys
  • ssh fingerprint
• Python
  • altinstall
• WordPress
  • Wordpress
• WP Web Design/config Stuff
  • Frontpage Display
  • Wordpress White Screen
  • wp-custom menu
• Magento
  • Magento Version/Edition
  • Indexing
• LXC-Containers
  • Overview/Installation
• Docker
  • Install
  • Basics
  • Creating Containers from images
  • Networking
  • Imaging & Pushing
  • Run Examples

RedHat7 134

• Systemctl
• Firewalld
  • General
  • Opening ports / services
• SELinux
  • Selinux
• Scheduling Tasks
  
• ACLs
  
  • Acls
  • Backup/Restore
• LDAP
  
• Adding Disks, Partitions and Filesystems
  
• Logical Volume Management (LVM)
  
• Accessing NFS
  
• Accessing SAMBA (SMB)