You can use a reservation policy to control how reservation requests are processed. When you provision machines from the blueprint, provisioning is restricted to the resources specified in your reservation policy.
Reservation policies provide an optional means of controlling how reservation requests are processed. You can apply a reservation policy to a blueprint to restrict the machines provisioned from that blueprint to a subset of available reservations.
You can use a reservation policy to collect resources into groups for different service levels, or to make a specific type of resource easily available for a particular purpose. When a user requests a machine, it can be provisioned on any reservation of the appropriate type that has sufficient capacity for the machine. The following scenarios provide a few examples of possible uses for reservation policies:
To ensure that provisioned machines are placed on reservations with specific devices that support NetApp FlexClone.
To restrict provisioning of cloud machines to a specific region containing a machine image that is required for a specific blueprint.
As an additional means of using a Pay As You Go allocation model for machine types that support that capability.
You can add multiple reservations to a reservation policy, but a reservation can belong to only one policy. You can assign a single reservation policy to more than one blueprint. A blueprint can have only one reservation policy.
Reservations defined for vCloud Air endpoints and vCloud Director endpoints do not support the use of network profiles for provisioning machines.
If you have SDRS enabled on your platform, you can allow SDRS to load balance storage for individual virtual machine disks, or all storage for the virtual machine. If you are working with SDRS datastore clusters, conflicts can occur when you use reservation policies and storage reservation policies. For example, if a standalone datastore or a datastore within an SDRS cluster is selected on one of the reservations in a policy or storage policy, your virtual machine storage might be frozen instead of driven by SDRS. If you request reprovisioning for a machine with storage placement on an SDRS cluster, the machine is deleted if the SDRS automation level is disabled. For related information about provisioning and SDRS, see the VirtualMachine.Admin.Datastore.Cluster.ResourceLeaseDurationSec custom property.