Choosing upgrade strategy
There are two ways to upgrade Plesk. The choice is made based on the server environment (the OS, installed third-party software, and system resources):
In-place upgrade is performed using Plesk Installer on the same server. This strategy 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. However, if the server has hosting software that is not supported by the target Plesk version (for example, hMailServer, MDaemon, or Gene6 FTP Server), it is strongly recommended to do an upgrade by transfer.
Note: the support for 32-bit OSes in Plesk Onyx has been dropped. Check Important Facts About and How to Upgrade to Plesk Onyx for more information.
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. Upgrade by transfer also allows to minimise downtime of services on the production server, as websites stay online while the transfer is in progress.
The other factors that may affect the choice are listed in Plesk documentation. This guide will help you perform an in-place upgrade of Plesk. If you prefer to let Plesk professionals handle the migration or upgrade job for you, please check out Plesk professional services options on our website.
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). If the OS is close to its end of life, it is recommended to upgrade by transfer: set up the new server with a modern OS and the latest version of Plesk and use Plesk Migrator to copy data from the old server.
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 Onyx may be unsuccessful, as this version does not support hMailServer. In such case, upgrade by transfer is recommended.
- The minimum hardware requirements should be met.
The current version of Plesk should support upgrading to Plesk Onyx. The supported versions are:
- for versions below 11.0.9, a two-step upgrade can be performed: first to 11.0.9, and then to Plesk Onyx.
- for version 9.5 or earlier, it is recommended to set up a new server with Plesk Onyx, 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)
/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
apt, depending on the type of Linux distribution.
Either graphical, or command line interface can be used for the upgrade. To start the upgrade in GUI, go to Tools & Settings > Updates and Upgrades > Install or Upgrade Product (more details are available in Plesk documentation). Instructions on how to start the upgrade via command line are available in the article How to update or upgrade Plesk installation through the command line.
If Plesk is installed in a container using Virtuozzo containers templates, consider performing an upgrade using templates. See full list of instructions in the article #213389329.
If an upgrade procedure on Linux has been started via SSH session, make sure the connection is not interrupted before the upgrade process finishes. The best practice is using the screen console manager, which allows multiple console sessions over a single SSH connection and keeps programs running in virtual terminals, even if the SSH connection is interrupted. On Windows, persistent connection is not a concern, as Windows preserves applications and keeps them running, even after a remote desktop session is disconnected.
Note: when the upgrade process is running, do not interrupt Plesk Installer or reboot the server.
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
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