A XenServer vApp is a logical group of one or more related virtual machines (VMs) which can be managed as a single entity. The VMs within a vApp do not have to reside on one host server and will be distributed within a pool using the normal rules.

When a vApp is started, the VMs contained within it will start in a user-defined order, allowing VMs which depend upon one another to be automatically sequenced. This means that you do not need to manually sequence the startup of dependent VMs should a whole service require restarting, for instance in the case of a software update.

Using the Manage vApps dialog box

Use the XenCenter Manage vApps dialog box you can create, delete and modify vApps, start and shutdown vApps, and import and export vApps within the selected pool. When you select a vApp in the list, the VMs it contains are listed in the details pane on the right.

Control

Function

New vApp

Opens the New vApp wizard. See Create a vApp.

Delete

Deletes the selected vApp. The VMs in the vApp will not be deleted.

Properties

Opens a Properties dialog box for the selected vApp. Here you can change its name or description, add or remove VMs from the vApp, and change their start order and delay interval. See Modify vApps.

Start

Starts up all of the VMs in the selected vApp in the sequence specified by the start order and delay interval values set on each individual VM. See Start and shut down vApps.

Shut Down

Shut down all of the VMs in the selected vApp. See Start and shut down vApps.

Import

Open Import wizard and import an OVF/OVA package as a vApp. See Export and import vApps.

Export

Open the Export wizard and export a vApp as an OVF/OVA package. See Export and import vApps.

Create a vApp

To create a new vApp, use the Manage vApps dialog box.

1. Select the pool and, from the Pool menu, click Manage vApps.Alternatively, right-click in the Resources pane and click Manage vApps on the shortcut menu.

2. Click New vApp… on the top left corner of the Manage vApps dialog box.

3. Enter the name of the new vApp and (optionally) a description, then click Next. You can choose any name you like, but a descriptive name is usually best. Although it is advisable to avoid having multiple vApps with the same name, it is not a requirement, and XenCenter does not enforce any uniqueness constraints on vApp names. It is not necessary to use quotation marks for names that include spaces.

4. Choose which virtual machines to include in the new vApp and then click Next. You can use the Search box to list only VMs with names that include the specified string.

5. Specify the startup sequence for the VMs in the vApp, and then click Next.

   Value

   Description

   Start order

   Specifies the order in which individual VMs will be started up within the vApp, allowing certain VMs to be restarted before others. VMs with a start order value of 0 (zero) will be started first, then VMs with a start order value of 1, then VMs with a start order value of 2, and so on.

   Attempt to start next VM after

   This is a delay interval that specifies how long to wait after starting the VM before attempting to start the next group of VMs in the startup sequence, that is, VMs with a lower start order.

   Note that the shutdown order of VMs in a vApp is always the reverse of the configured start order.

6. On the final page of the wizard, you can review the vApp configuration. Click Previous to go back and modify any settings, or Finish to create the new vApp and close the wizard.

Export and Import vApps

To export a vApp

vApps can be exported as OVF/OVA packages.

1. Open the Manage vApps dialog box: on the Pool menu, click Manage vApps.
2. Select the vApp you want to export in the list and click  Export.
3. Follow the procedure described in Export VMs as OVF/OVA.Exporting a vApp may take some time.

To import a vApp

OVF/OVA packages are imported as vApps.

1. Open the Manage vApps dialog box: on the Pool menu, click Manage vApps.
2. Click  Import to open the Import wizard.
3. Follow the procedure described in Import VMs from OVF/OVA.When the import is complete, the new vApp appears in the list of vApps in the Manage vApps dialog box.

Start and Shut Down vApps

To start or shut down a vApp, use the Manage vApps dialog box, accessed from the Pool menu.When you start a vApp, all the VMs within it are started up automatically in sequence. The start order and delay interval values specified for each individual VM control the startup sequence; these values can be set when you first create the vApp and changed at any time from the vApp Properties dialog box or from the individual VM’s Properties dialog box.The shutdown order of VMs in a vApp is always the reverse of the configured start order.

To start a vApp

1. Open the Manage vApps dialog box: select the pool where the VMs in the vApp are located and, on the Pool menu, click Manage vApps.Alternatively, right-click in the Resources pane and click Manage vApps on the shortcut menu.
2. Select the vApp and click  Start to start all of the VMs it contains.

To shut down a vApp

1. Open the Manage vApps dialog box: select the pool where the VMs in the vApp are located and, on the Pool menu, click Manage vApps.Alternatively, right-click in the Resources pane and click Manage vApps on the shortcut menu.
2. Select the vApp and click  Shut Down to shut down all of the VMs in the vApp. A soft shut down will be attempted on all VMs; if this is not possible, then a forced shut down will be performed. See Shut down a VM to find out more about soft and forced VM shutdowns.

Delete a vApp

To delete a vApp from a pool, use the Manage vApps dialog box.

1. Select the pool and, on the Pool menu, click Manage vApps.Alternatively, right-click in the Resources pane and click Manage vApps on the shortcut menu.
2. Select the vApp you want to delete from the list, then click  Delete.The VMs in the vApp will not be deleted.