Unlike the Deploy new vApp option, which allows you to quickly build a virtual server from a template, composing a vApp lets you deploy a new vApp including multiple virtual servers from templates, create a copy of an existing vApp, or create a blank vApp to prepare for an import of an existing machine.
To compose a custom vApp, from the vApps menu item select the Compose vApp button. If you're creating a blank vApp for a to-be imported machine, set blank vApp to enabled, then provide a name for your vApp and click compose.
To add multiple virtual servers from templates, or from any existing servers in your private catalogue, set the vApp's name, then from the vApp templates field select the templates you wish to be deployed within the vApp.
To copy an existing vApp from within your organisation, do not select any vApp templates, instead select the desired vApp from the vApps dropdown.
Once done, click Compose, and the vApp will be created.
It's important to note that, as this is a custom vApp, you will not be walked through the vApp deployment wizard and that each virtual server will be deployed with the recommended minimum specifications for template deployments, or matching the existing configuration for a clone of an existing vApp. To edit the resources, navigate to your virtual server, then click Tools > Edit resources. Here you can set the desired resource level for your virtual servers.
For all other changes, please see the relevant articles in this KB section.