When a member of a business group requests a physical machine, vRealize Automation must select a machine from one of the group’s physical reservations.
The reservation from which a machine is provisioned must satisfy the following criteria:
The reservation must be a physical reservation.
The reservation must be enabled.
The reservation must have capacity remaining in its machine quota or have an unlimited quota.
The reservation must contain an unprovisioned machine matching the blueprint specifications.
If the blueprint or request specifies a location, the compute resource must be associated with that location.
If the blueprint specifies a reservation policy, the reservation must belong to that reservation policy.
Reservation policies are a way to guarantee that the selected reservation satisfies any additional requirements for provisioning machines from a specific blueprint.
For example, although a physical reservation is not restricted to a particular hardware type, the best practice is to create reservations with only one type of physical machine and use reservation policies to restrict provisioning from blueprints of a specific type to reservations containing only machines of that type. This allows you to ensure that your HP iLO blueprints are correct for HP iLO provisioning, and so on. For example, when you use a custom property in a blueprint to specify the location of a boot disk, the value is a web URL for HP iLO machines but an NFS or CIFS path for Dell iDRAC machines.
If no reservation is available that meets all of the selection criteria, provisioning fails.
If multiple reservations meet all of the criteria, the reservation from which to provision a requested machine is determined by the following logic:
Reservations with higher priority are selected over reservations with lower priority.
If multiple reservations have the same priority, the reservation with the lowest percentage of its machine quota allocated is selected.
If multiple reservations have the same priority and quota usage, machines are distributed among reservations in round-robin fashion.
If there are multiple unprovisioned machines in the selected reservation, machine is selected for provisioning by the following process:
The first machine is evaluated against the resource specifications in the blueprint, including the resource matching settings. For example, at least 2 CPUs and exactly 2 GB of memory, or exactly 4 CPUs and 4 GB.
If the machine matches the specifications, it is selected for provisioning. If it does not, the next machine in sequence is evaluated, and so on.