(Optional) Optimize Plesk for Operation in VPS

If you deploy Plesk in Virtuozzo for Linux, consider switching Plesk to a special mode of operation - optimized for virtual environments. The mode switches off InnoDB engine in MySQL database server, and Apache web server modules that are not critical for hosting services. This makes Plesk use less memory than other control panels available on the market, which ensures better utilization of hardware resources and increased density of virtual environments per server.

The only disadvantages of using the optimized mode are as follows:

  • Web applications requiring InnoDB will not work.
  • Perl, python and ASP scripts will not work because the required Apache modules will be switched off (see the list below).
  • PHP will be available only through CGI.

Note: The optimized mode can be switched on only on the clean Plesk installations. It is not applicable to the Plesk installations upgraded from earlier versions.

To switch to the VPS-optimized mode:

Install the pp12-vps-optimized EZ template. The template applies the necessary configuration.

Important: The optimized mode can only be enabled on fresh installations of Plesk which have not yet been initialized, or, in other words, have not undergone the initial configuration.

If you need to switch Plesk back to the normal mode of operation, perform the following steps:

  1. Switch on the InnoDB engine.
    1. Open for editing the file /etc/my.cnf.
    2. Locate the lines containing entries skip-innodb and remove them, or comment them out.
    3. Save the file.
    4. Restart MySQL server.
  2. Switch on the required Apache modules.

    On Debian Linux, use the a2enmod utility to switch on all required modules. For example, if you want to switch on the PHP module, issue the following command:

    a2enmod php5

    On other distributions of Linux, edit the main Apache configuration file, which, in most Linux installations, is located in /etc/httpd/conf/.

    1. Open for editing the file /etc/httpd/conf/httpd.conf.
    2. Locate the lines LoadModule <module_name> corresponding to the modules that you want to switch on, and uncomment the lines.
    3. Save the file.
    4. Restart Apache.
  3. Switch Plesk back to normal operation mode by issuing the following SQL query:

    mysql -uadmin -p`cat /etc/psa/.psa.shadow` psa -e "update misc set val='0' where param='vps_optimized_mode_status';"

Apache Modules Switched Off in VPS-Optimized Mode

The following Apache modules are switched off in the optimized mode:

  • authn_alias
  • authn_anon
  • authn_dbm
  • authn_default
  • authz_user
  • authz_owner
  • authz_groupfile
  • authz_dbm
  • authz_default
  • ldap
  • authnz_ldap
  • ext_filter
  • mime_magic
  • deflate
  • usertrack
  • dav_fs
  • vhost_alias
  • speling
  • proxy_balancer
  • cache
  • disk_cache
  • file_cache
  • mem_cache
  • version
  • asis
  • bw
  • proxy_ajp
  • auth_ldap
  • perl
  • python
  • php5
  • php4

The list of the modules can vary depending on the operating system distribution and architecture. When Plesk is installed and the optimized mode is switched on, you can check the list in the following files:

  • On 32-bit operating systems - /usr/lib/plesk-12.0/vps_optimized_aspects/apache-modules-all
  • On 64-bit operating systems - /usr/lib64/plesk-12.0/vps_optimized_aspects/apache-modules-all