CloudLinux ELevate: Plesk now also moves from CloudLinux 8 to 9 in-place

Anyone running a Plesk server on CloudLinux 8 can now move to CloudLinux 9 without reinstalling the operating system or migrating accounts and sites to a new machine. The tool is called cloudlinux8to9, provided and maintained by the Plesk team, and it internally calls CloudLinux ELevate to carry out the actual operating system upgrade. This is reported on the CloudLinux blog. On a Plesk server, this tool must be run instead of ELevate on its own.

Why Plesk has a separate tool

The September 2025 release of ELevate for upgrading from CloudLinux 8 to 9 covered cPanel, DirectAdmin and servers without a control panel, leaving Plesk for a separate release. Plesk's converter stops Plesk before the operating system upgrade and restores its services, configuration and databases once it's finished. The same approach was already used by cloudlinux7to8 for the move from CloudLinux 7 to 8.

Requirements and timing

The server must be running CloudLinux 8.10 and a Plesk version no more than five releases behind the latest available one, and it cannot be a container (for example Virtuozzo or Docker). The tool checks these and other requirements before starting, and halts if any of them isn't met.

Throughout the conversion, websites, email and Plesk itself are unreachable, the server reboots three times, and the whole operation can take several hours: it should be scheduled for a low-traffic period. Before starting, it's worth backing up the databases and taking a snapshot to roll back to in case of problems, and making sure you can reach the server even without SSH — for example via a serial console — since during the intermediate phase the system temporarily runs without networking.

The known issue with MariaDB 10.3

On servers running MariaDB 10.3 alongside MySQL Governor — which limits database usage for each hosting account — the conversion doesn't complete: the tool's checks let 10.3 through, the server reaches CloudLinux 9, then MariaDB starts throwing errors and the final stage fails. The issue is specific to version 10.3. CloudLinux is working on a fix; in the meantime, the workaround is to upgrade MariaDB to 10.6 before starting the conversion.

The step-by-step guide is available in the Plesk knowledge base, How to make an in-place upgrade of a Plesk server from CloudLinux 8 to CloudLinux 9; the tool's README on GitHub shows the current version. For questions about the cloudlinux8to9 tool, contact Plesk; for questions about ELevate and CloudLinux packages, contact CloudLinux support.