Parallels H-Sphere Documentation Administrator Guide


Server Groups


Last modified: 19 Jun 2008


WARNING: This documentation covers Parallels H-Sphere versions up to 3.1. For the latest up-to-date Parallels H-Sphere documentation, please proceed to the official Parallels site.

Logical servers are grouped by functionality and purpose. For instance, you can have a group of name servers, a group of 'priority' web servers, a group of 'basic' web servers etc. Logical server groups allow you to control the distribution of user data across servers.

Example: You have several customers on a priority hosting plan and you want to keep their sites on a separate box. To achieve this, you need to create a separate 'priority web' server group and add it to this box.

You can add one server group to many physical servers. For instance, if you add the 'priority web' server group to p.server1, p.server2, and p.server3, your priority plan customers will be randomly distributed across these three physical servers.

A physical server may have one or many server groups. For instance, you can add the 'priority web' server group to p.server1 and p.server2, whereas all other server groups can be added to p.server3.

Note: You can't add a logical server to a physical server if it doesn't have the respective server group.

Consider another example:

Let's say you've got:

  • p.server1 with the following groups on it: Control Panel, Mail, Web, Name and
  • p.server2 with Mail, Real and MySQL server groups.

In this case logical servers:

  •,, can be set up only on ph_server_1 and with - on ph_server_2;
  • while can be set up to any of them.

    You can also have two logical servers carrying out mail service (e.g.: and set up on different or the same physical server. Several different web, name, etc., logical servers can be put on one physical server, too. The only requirement is that it has the appropriate server group.

To see the server groups available in your system, go to E.Manager-> Servers -> Server Groups:


How Do I Create a Server Group?

  1. Go to E.Manager -> Servers -> Server Groups.
  2. At the bottom of the page that appears, enter the name of the server group and select its type.
  3. Click Add.


How Do I Add a Group to a Physical Server?

  1. Go to E.Manager-> Servers -> P.Servers.
  2. Click the name of the physical server.
  3. At the bottom of the page that appears, select a server group and click Add.
  4. Now you can create logical servers in this server group.


How Do I Delete a Server Group?

You can delete only custom server groups by clicking the Delete icon next to them.


How Do I Enable/Disable Resources for a Particular Server Group?

Starting with H-Sphere 3.1, you can enable or disable some resources on the level of logical server groups, no matter if they are installed on physical servers or not. Before enabling/disabling resources, make sure Resources Prerequisites feature is enabled in Globals. A special background job BoxesInfoCron checks if the resources with prerequisites are installed on physical boxes. If some resources prerequisites are enabled in Logical Server Groups, but are not installed correctly physically, an exclamation mark appears next to the corresponding logical server in E.Manager - > Servers -> L.Servers.

The Resource Prerequisites feature implies the following:
  1. Some resources can be enabled/disabled for selected logical server groups despite their availability on physical boxes.
  2. The background job checks if the resources with prerequisites are installed physically.
  3. Enabling/disabling of resources automatically affects end users, without a need of editing respective plans.

More on Resource Prerequisites.


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