If you run Plesk on CloudLinux 8, you can now upgrade the server to CloudLinux 9 in place, without reinstalling it or moving accounts and sites to a new machine. The conversion runs through cloudlinux8to9, a tool provided and maintained by the Plesk team, and CloudLinux ELevate does the operating-system upgrade inside it. On a Plesk server, run this tool rather than ELevate on its own. Plesk published it on 24 September, with step-by-step instructions in its knowledge base.

Why Plesk servers have their own tool

ELevate’s CloudLinux 8 to 9 release in September 2025 covered cPanel, DirectAdmin and servers without a control panel, and left Plesk for a separate release. Plesk’s converter stops Plesk before the operating-system upgrade and restores its services, configuration and databases afterwards. Plesk’s cloudlinux7to8 did the same for the move from CloudLinux 7 to 8.

Before you start

The server needs CloudLinux 8.10 and a Plesk release no more than five versions behind the latest, and it can’t be a container, such as Virtuozzo or Docker. The tool checks these and its other requirements before it starts, and stops if one isn’t met.

Plan for the downtime. Websites, email and Plesk are unavailable for the whole conversion, the server reboots three times, and the run can take up to several hours, so pick a quiet time.

Back up your databases and take a snapshot you can return to. Make sure you can reach the server without SSH, through a serial console for example, because in the middle stage it runs a temporary system with no network.

If you use MariaDB 10.3 with MySQL Governor, wait for the fix

MySQL Governor limits each hosting account’s database usage. On servers that use it with MariaDB 10.3, the conversion doesn’t complete yet. The tool’s checks let 10.3 through, so the server reaches CloudLinux 9, then MariaDB starts crashing and the last stage of the conversion fails. The problem is specific to MariaDB 10.3.

A fix from CloudLinux is on its way. Wait for our update to this post saying it has reached every server, or upgrade MariaDB to 10.6 before you start.

Where to find the step-by-step guide

Plesk’s knowledge base article, How to make an in-place upgrade of a Plesk server from CloudLinux 8 to CloudLinux 9, walks through the conversion, the special cases and troubleshooting. The tool’s README on GitHub has the current steps and release, and our ELevate documentation covers ELevate itself.

Questions about the cloudlinux8to9 tool go to Plesk. Questions about ELevate and CloudLinux packages go to CloudLinux support.