Una template es una configuración reutilizable de una máquina virtual. Más concretamente es una imagen de disco virtual que contiene un sistema operativo ya instalado y configurado. Los usuarios pueden crear templates a partir de una máquina virtual, a partir del snapshot de un disco y a partir de [en.wikipedia.org/wiki/VHD_(file_format)|VHD] de otros sistemas. Las templates pueden ser públicas o privadas. Como su propio nombre indica una template privada sólo puede ser vista y utilizada por el usuario que la creó, mientras que las públicas pueden ser vistas y usadas por todos los usuarios.

El punto de partida es una máquina virtual ya creada y configurada para que sirva de prototipo. Tiene que estar parada.

  Click Create Template and provide the following:
      Name and Display Text. These will be shown in the UI, so choose something descriptive.
      OS Type. This helps CloudStack and the hypervisor perform certain operations and make assumptions that improve the performance of the guest. Select one of the following.
          If the operating system of the stopped VM is listed, choose it.
          If the OS type of the stopped VM is not listed, choose Other.
          If you want to boot from this template in PV mode, choose Other PV (32-bit) or Other PV (64-bit). This choice is available only for XenServere:
          Note
          Note: Generally you should not choose an older version of the OS than the version in the image. For example, choosing CentOS 5.4 to support a CentOS 6.2 image will in general not work. In those cases you should choose Other. 
      Public. Choose Yes to make this template accessible to all users of this CloudStack installation. The template will appear in the Community Templates list. See Section 12.5, “Private and Public Templates”.
      Password Enabled. Choose Yes if your template has the CloudStack password change script installed. See Section 12.13, “Adding Password Management to Your Templates”. 
  Click Add. 

The new template will be visible in the Templates section when the template creation process has been completed. The template is then available when creating a new VM.