9.2. Virtual Machine Pool Tasks

9.2.1. Creating a Virtual Machine Pool

You can create a virtual machine pool that contains multiple virtual machines that have been created based on a common template.

Procedure 9.1. Creating a Virtual Machine Pool

  1. Click the Pools tab.
  2. Click the New button to open the New Pool window.
  3. Use the drop down-list to select the Cluster or use the selected default.
  4. Use the Template drop-down menu to select the required template and version or use the selected default. A template provides standard settings for all the virtual machines in the pool.
  5. Use the Operating System drop-down list to select an Operating System or use the default provided by the template.
  6. Use the Optimized for drop-down list to optimize virtual machines for either Desktop use or Server use.
  7. Enter a Name and Description, any Comments, and the Number of VMs for the pool.
  8. Enter the number of virtual machines to be prestarted in the Prestarted VMs field.
  9. Select the Maximum number of VMs per user that a single user is allowed to run in a session. The minimum is one.
  10. Select the Delete Protection check box to enable delete protection.
  11. Optionally, click the Show Advanced Options button and perform the following steps:
    1. Click the Type tab and select a Pool Type:
      • Manual - The administrator is responsible for explicitly returning the virtual machine to the pool. The virtual machine reverts to the original base image after the administrator returns it to the pool.
      • Automatic - When the virtual machine is shut down, it automatically reverts to its base image and is returned to the virtual machine pool.
    2. Select the Console tab. At the bottom of the tab window, select the Override SPICE Proxy check box to enable the Overridden SPICE proxy address text field. Specify the address of a SPICE proxy to override the global SPICE proxy.
  12. Click OK.
You have created and configured a virtual machine pool with the specified number of identical virtual machines. You can view these virtual machines in the Virtual Machines resource tab, or in the details pane of the Pools resource tab; a virtual machine in a pool is distinguished from independent virtual machines by its icon.

9.2.2. Explanation of Settings and Controls in the New Pool and Edit Pool Windows

9.2.2.1. New Pool and Edit Pool General Settings Explained

The following table details the information required on the General tab of the New Pool and Edit Pool windows that are specific to virtual machine pools. All other settings are identical to those in the New Virtual Machine window.

Table 9.1. General settings

Field Name
Description
Template
The template on which the virtual machine pool is based.
Description
A meaningful description of the virtual machine pool.
Comment
A field for adding plain text human-readable comments regarding the virtual machine pool.
Prestarted VMs
Allows you to specify the number of virtual machines in the virtual machine pool that will be started before they are taken and kept in that state to be taken by users. The value of this field must be between 0 and the total number of virtual machines in the virtual machine pool.
Number of VMs/Increase number of VMs in pool by
Allows you to specify the number of virtual machines to be created and made available in the virtual machine pool. In the edit window it allows you to increase the number of virtual machines in the virtual machine pool by the specified number. By default, the maximum number of virtual machines you can create in a pool is 1000. This value can be configured using the MaxVmsInPool key of the engine-config command.
Maximum number of VMs per user
Allows you to specify the maximum number of virtual machines a single user can take from the virtual machine pool at any one time. The value of this field must be between 1 and 32,767.
Delete Protection
Allows you to prevent the virtual machines in the pool from being deleted.

9.2.2.2. New and Edit Pool Type Settings Explained

The following table details the information required on the Type tab of the New Pool and Edit Pool windows.

Table 9.2. Type settings

Field Name
Description
Pool Type
This drop-down menu allows you to specify the type of the virtual machine pool. The following options are available:
  • Automatic: After a user finishes using a virtual machine taken from a virtual machine pool, that virtual machine is automatically returned to the virtual machine pool.
  • Manual: After a user finishes using a virtual machine taken from a virtual machine pool, that virtual machine is only returned to the virtual machine pool when an administrator manually returns the virtual machine.

9.2.2.3. New Pool and Edit Pool Console Settings Explained

The following table details the information required on the Console tab of the New Pool or Edit Pool window that is specific to virtual machine pools. All other settings are identical to those in the New Virtual Machine and Edit Virtual Machine windows.

Table 9.3. Console settings

Field Name
Description
Override SPICE proxy
Select this check box to enable overriding the SPICE proxy defined in global configuration. This feature is useful in a case where the user (who is, for example, connecting via the User Portal) is outside of the network where the hypervisors reside.
Overridden SPICE proxy address
The proxy by which the SPICE client will connect to virtual machines. This proxy overrides both the global SPICE proxy defined for the Red Hat Enterprise Virtualization environment and the SPICE proxy defined for the cluster to which the virtual machine pool belongs, if any. The address must be in the following format: 
protocol://[host]:[port]

9.2.3. Editing a Virtual Machine Pool

9.2.3.1. Editing a Virtual Machine Pool

After a virtual machine pool has been created, its properties can be edited. The properties available when editing a virtual machine pool are identical to those available when creating a new virtual machine pool except that the Number of VMs property is replaced by Increase number of VMs in pool by.

Procedure 9.2. Editing a Virtual Machine Pool

  1. Click the Pools resource tab, and select a virtual machine pool from the results list.
  2. Click Edit to open the Edit Pool window.
  3. Edit the properties of the virtual machine pool.
  4. Click Ok.

9.2.3.2. Prestarting Virtual Machines in a Pool

The virtual machines in a virtual machine pool are powered down by default. When a user requests a virtual machine from a pool, a machine is powered up and assigned to the user. In contrast, a prestarted virtual machine is already running and waiting to be assigned to a user, decreasing the amount of time a user has to wait before being able to access a machine. When a prestarted virtual machine is shut down it is returned to the pool and restored to its original state. The maximum number of prestarted virtual machines is the number of virtual machines in the pool.
Prestarted virtual machines are suitable for environments in which users require immediate access to virtual machines which are not specifically assigned to them. Only automatic pools can have prestarted virtual machines.

Procedure 9.3. Prestarting Virtual Machines in a Pool

  1. Use the Pools resource tab, tree mode, or the search function to find and select the virtual machine pool in the results list.
  2. Click Edit to open the Edit Pool window.
  3. Enter the number of virtual machines to be prestarted in the Prestarted VMs field.
  4. Select the Pool tab. Ensure Pool Type is set to Automatic.
  5. Click OK.
You have set a number of prestarted virtual machines in a pool. The prestarted machines are running and available for use.

9.2.3.3. Adding Virtual Machines to a Virtual Machine Pool

If you require more virtual machines than originally provisioned in a virtual machine pool, add more machines to the pool.

Procedure 9.4. Adding Virtual Machines to a Virtual Machine Pool

  1. Use the Pools resource tab, tree mode, or the search function to find and select the virtual machine pool in the results list.
  2. Click Edit to open the Edit Pool window.
  3. Enter the number of additional virtual machines to add in the Increase number of VMs in pool by field.
  4. Click OK.
You have added more virtual machines to the virtual machine pool.

9.2.3.4. Detaching Virtual Machines from a Virtual Machine Pool

You can detach virtual machines from a virtual machine pool. Detaching a virtual machine removes it from the pool to become an independent virtual machine.

Procedure 9.5. Detaching Virtual Machines from a Virtual Machine Pool

  1. Use the Pools resource tab, tree mode, or the search function to find and select the virtual machine pool in the results list.
  2. Ensure the virtual machine has a status of Down because you cannot detach a running virtual machine.
    Click the Virtual Machines tab in the details pane to list the virtual machines in the pool.
  3. Select one or more virtual machines and click Detach to open the Detach Virtual Machine(s) confirmation window.
  4. Click OK to detach the virtual machine from the pool.

Note

The virtual machine still exists in the environment and can be viewed and accessed from the Virtual Machines resource tab. Note that the icon changes to denote that the detached virtual machine is an independent virtual machine.
You have detached a virtual machine from the virtual machine pool.

9.2.4. Removing a Virtual Machine Pool

You can remove a virtual machine pool from a data center. You must first either delete or detach all of the virtual machines in the pool. Detaching virtual machines from the pool will preserve them as independent virtual machines.

Procedure 9.6. Removing a Virtual Machine Pool

  1. Use the Pools resource tab, tree mode, or the search function to find and select the virtual machine pool in the results list.
  2. Click Remove to open the Remove Pool(s) confirmation window.
  3. Click OK to remove the pool.
You have removed the pool from the data center.