After a template is created, Parallels RAS begins creating hosts from it, one virtual machine at a time. The number of VMs created at this time is determined by the Number of hosts deployed on the wizard completion property (all property names here and later refer to the Create Template Wizard described earlier).
The number of VMs available at any time will never go below the number specified in the Keep available buffer property. To comply with this rule, a new VM is automatically created when needed. At the same time, the total number of VMs will never exceed the number specified in the Maximum hosts property.
Please note that creating a new host from a template takes some time, especially when a template is configured to create full clones (linked clones are created much faster). If a host is in the middle of being created, and no other VMs are available, a user (or users) who need it will have to wait until the VM is ready.
If a host encounters a problem during the preparation stage, it will remain on the server in unusable state. You can identify such VMs by the Failed to create value in the Status column. Unless a VM like this is repaired or recreated, it will be automatically removed after the time period specified in the Auto remove hosts which failed preparation after field in Site defaults (Farm > <Site> > VDI > Desktops > Tasks > Site defaults). You can view the details of the failure to create a host by clicking on the Details link in the Status column or double-clicking the column. You can also choose Recreate or Delete from the same menu. For more information on how to recreate a host, please see the Template maintenance section.
A host is automatically deleted when it is not used longer than specified in the Delete unused hosts after field in template properties.