vApps

A vApp is a logical group of one or more related Virtual Machines (VMs) which can be started up as a single entity. When a vApp is started, the VMs contained within the vApp start in a user predefined order, to allow VMs which depend upon one another to be automatically sequenced. This means that an administrator no longer has to manually sequence the startup of dependent VMs should a whole service require restarting (for instance in the case of a software update). The VMs within the vApp do not have to reside on one host and will be distributed within a pool using the normal rules.

The vApp functionality is useful in the Disaster Recovery situation where an Administrator may choose to group all VMs which reside on the same Storage Repository, or which relate to the same Service Level Agreement (SLA).

Note

vApps can be created and modified using both XenCenter and the xe CLI. For information on working with vApps using the CLI, see the XenServer Administrator’s Guide.

Managing vApps in XenCenter

XenCenter’s Manage vApps dialog box allows you to 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.

To change the name or description of a vApp, add or remove VMs from the vApp, and change the startup sequence of the VMs in the vApp, 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 and click Properties to open its Properties dialog box.

  3. Click the General tab to change the vApp name or description.

  4. Click the Virtual Machines tab to add or remove VMs from the vApp.

  5. Click the VM Startup Sequence tab to change the start order and delay interval values for individual VMs in the vApp.

  6. Click OK to save your changes and close the Properties dialog box.

See the XenCenter help for further details. Press F1 or click Help to display the Help.

Creating vApps

To group VMs together in a vApp follow the procedure:

  1. Select the pool and, on the Pool menu, click Manage vApps. This displays the Manage vApps window.

  2. Enter a name for the vApp, and optionally a description, and then click Next.

    You can choose any name you like, but a descriptive name is 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.

  3. Choose which VMs 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.

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

    • 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.
  5. 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 vApp and close the wizard.

Note

A vApp can span across multiple servers in a single pool, but cannot span across several pools.

Deleting vApps

To delete a vApp follow the procedure:

  1. Select the pool and, on the Pool menu, click Manage vApps.

  2. Select the vApp you want to delete from the list, then click Delete.

Note

The VMs in the vApp will not be deleted.

Start and Shutdown vApps using XenCenter

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 Properties dialog box.

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 shutdown will be attempted on all VMs. If this is not possible, then a forced shutdown will be performed.

    Note

    A soft shutdown performs a graceful shutdown of the VM, and all running processes are halted individually.

    A forced shutdown performs a hard shutdown and is the equivalent of unplugging a physical server. It may not always shut down all running processes and you risk losing data if you shut down a VM in this way. A forced shutdown should only be used when a soft shutdown is not possible.

Importing and Exporting vApps

vApps can be imported and exported as OVF/OVA packages. See Importing and Exporting VMs for more details.

To export a vApp

  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 Exporting OVAs.

Exporting a vApp may take some time.

To import a vApp

  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 Importing OVAs.

When the import is complete, the new vApp appears in the list of vApps in the Manage vApps dialog box.