Note: We recommend trying out the Release Candidate using backed up production data, but do not recommend using it in live production environments.
Choosing an upgrade strategy
There are two ways to upgrade Plesk:
In-place upgrade is performed using Plesk Installer on the same server. Can be used if the OS installed on the server is supported by the target Plesk version and is not discontinued under the terms of the Plesk Lifecycle Policy.
Upgrade by transfer is the process of switching to the latest Plesk version by moving all of the hosting data and settings from the current Plesk server to a server with the latest version of Plesk installed. This strategy is preferred when upgrading servers with an OS that either not supported or is approaching the support termination date.
Before you start
Make sure the server has enough resources and meets all requirements:
OS version should be supported by its vendor and not approaching its termination date (check the Plesk Lifecycle Policy page).
In case of Upgrade by transfer strategy, the server should meet the target version's software requirements and that all software installed on the server is compatible with the target version. For example, if the server has hMailServer installed and set up as a mail server in Plesk, then upgrading to Plesk Obsidian may be unsuccessful, as this version does not support hMailServer. In such case, upgrade by transfer is recommended.
In case of In-place upgrade, the installed version of Plesk should support upgrading to Plesk Obsidian. The supported versions are:
- Plesk Onyx 17.0
- Plesk Onyx 17.5
- Plesk Onyx 17.8
If an earlier version is installed you can either upgrade to Plesk Onyx first or set a new server with Plesk Obsidian and then transfer the accounts and websites to the new server. Please see Plesk Migration and Transfer Guide for details.
At least 3GB of free disk space should be available for each of the following directories:
- On Windows:
(see #213903325 for the reference)
- On Linux:
/opt/psaon Debian and Ubuntu) and
/tmp(if it is mounted to a separate partition)
- On Windows:
- On Linux: it should be possible to execute files in the
/tmpdirectory. Check that directory is not mounted with
# mount -l | grep noexec
If it is, remount the directory without the
# mount -o remount,exec /tmp
- On Linux: verify that the system package manager is configured properly and can fetch and install packages from the OS vendor's repositories (see the article How to check system repositories configuration). Note that there is no need to disable third-party repositories before the upgrade. Also, the latest OS updates should be applied using
apt, depending on the type of Linux distribution.
- On Windows: MySQL should be used as a Plesk database provider. To determine which database provider is used to storing the Plesk configuration database, use the article #213922485. If the Plesk database provider is Jet or MS SQL, switch it to MySQL using the instructions provided in article #213921345. It will save time during the upgrade.
- Download and run the latest pre-upgrade checker. If a problem is found, it is reported as a warning in the final report. The log file will have a full description of the issue with a link to a helpful KB article. Apply the solutions, then re-run the pre-upgrade checker until no warnings are reported or only non-critical issues (such as business logic warnings) are left.
- "Known Problems and Limitations" section of Plesk Upgrade Notes should be read and the necessary actions are taken.
- The upgrade should be scheduled on the time when the server load is the lowest and the service downtime impact on hosting customers is minimal.
- All scheduled maintenance tasks should be temporarily disabled, as they may interfere with the upgrade process (especially, on Windows).
- It is a good idea to make a full server backup, which can be used to re-image the server if needed
How to start the upgrade
Detailed instruction can be found in How to upgrade Plesk to the next release
If there is no output from Plesk Installer for a long time, it does not mean that the upgrade has stuck. Some silent background operation might be taking a long time to run. Check what is happening on the server:
On Linux, run the
ps axufwwcommand and check the process tree that stems from the Plesk Installer process. See if any of these processes are running ("R" state). Run the command several times with an interval of 1-3 minutes and check if there is any change.
On Windows, download Process Explorer, unpack and run it. Check the process tree and see if any child processes of
ai.exeare consuming CPU or opening/closing files.
If the upgrade fails, check for error messages in the output, as well as in the log files (
C:\ParallelsInstaller\autoinstaller3.logon Windows or
/var/log/plesk/install/plesk_17.0.17_installation.logon Linux). Check Plesk Knowledgebase for solutions using the found error messages.
To continue the failed upgrade, re-run
plesk-installer.exeon Windows or .
/plesk-installeron Linux, or use the following command:
# plesk repair installation