You can upgrade the operating system on a Plesk server in two ways:

• Migrate your Plesk server to a server with a later OS version using Plesk Migrator.
• Perform dist-upgrade.

We recommend that you use migration because dist-upgrade is not a simple process. To go through it you must have considerable experience in the system administration, the knowledge of the system and its components.

If you still decide to perform dist-upgrade, pay attention to the information below.

Plesk supports only the following dist-upgrade paths:

• Debian 9 to Debian 10
• Ubuntu 16 to Ubuntu 18
• Ubuntu 18 to Ubuntu 20

We do not recommend performing dist-upgrade together with Plesk updates. You need to update Plesk to the latest available version first and only then perform dist-upgrade.

For detailed procedures on performing dist-upgrade, refer to this KB article.