A vApp is logical group of one or more related Virtual Machines (VMs). vApps can be started up as a single entity when there is a disaster. When a vApp is started, the VMs contained within the vApp start in a user predefined order. The start order allows VMs which depend upon one another to be automatically sequenced. An administrator no longer has to manually sequence the startup of dependent VMs when a whole service requires restarting. For example, during a software update. The VMs within the vApp do not have to reside on one host and are distributed within a pool using the normal rules. The vApp feature is useful in the Disaster Recovery (DR) situation. In a DR scenario, an Administrator may group all VMs on the same Storage Repository, or which relate to the same Service Level Agreement (SLA).
To group VMs together in a vApp follow the procedure:
Select the pool and, on the Pool menu, click Manage vApps.
Type a name for the vApp, and optionally a description, and then click Next.
You can choose any name you like, but an informative name is best. Although we recommend you to avoid having multiple vApps using the same name, it is not a requirement. XenCenter does not enforce any constraints regarding unique vApp names. It is not necessary to use quotation marks for names that include spaces.
Select which VMs to include in the new vApp, and then click Next.
You can use the search option to list only VMs with names that include the specified text string.
Specify the startup sequence for the VMs in the vApp, and then click Next.
Start Order: Specifies the order in which individual VMs are started within the vApp, allowing certain VMs to be restarted before others. VMs with a start order value of 0 (zero) are started first. VMs with a start order value of 1 are started next, and then the VMs with a value of 2, and so on.
Attempt to start next VM after: 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.
You can review the vApp configuration on the final page. Click Previous to go back and change any settings, or Finish to create the vApp.
A vApp can span multiple servers in a single pool, but cannot span across several pools.
Manage vApps in XenCenter
The Manage vApps setting in XenCenter allows you to create, delete, and change vApps. It also enables you to start and shut down 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. For more information, see the XenCenter Help.