CloudLinux uses the fact that it is very close to CentOS and RHEL to convert systems in place, requiring just one reboot. Our conversion script does the following actions:
•Backup of original repository settings into /etc/cl-convert-saved.
•Backup of RHEL system id into /etc/cl-convert-saved (RHEL systems only).
•Installs CL repository settings & imports CL RPM key.
•Replaces redhat/centos-release, redhat-release-notes, redhat-logos with CL version.
•Removes cpuspeed RPM (as it conflicts with CPU limits).
•Re-installs CL version of rhnlib/rhnplugin.
•Checks for binary kernel modules, finds replacement if needed.
•Detects OVH servers and fixes mkinitrd issues.
•Detects Linode servers and fixes grub issues.
•Checks if LES is installed.
•Checks that /etc/fstab has correct /dev/root
•Checks for efi.
•Installs CL kernel, lve-utils, liblve, lve-stats RPMs.
•Installs LVE Manager for cPanel, Plesk, DirectAdmin, ISPManager & InterWorx
•Installs mod_hostinglimits apache module:
oRPM install for Plesk, ISPManager & InterWorx;
oOn Plesk, replaces psa-mod_fcgid* with mod_fcgid;
oEasyApache rebuild for cPanel;
ocustombuild for DA.
Script for converting back:
•Restores CentOS repositories, and centos-release/release-notes/logos.
•Removes lve, mod_hostinglimits, lve-stats, lvemanager.
•mod_hostinglimits RPM is removed.
The kernel is not removed - to prevent condition when server has no kernels and wouldn't boot. The command line to remove the kernel is provided.
On cPanel servers, rebuild of Apache with EasyApache will complete the conversion back, but doesn't have to be performed immediately.
On DirectAdmin servers, rebuild of Apache with custombuild will complete the conversion back, but doesn't have to be performed immediately.