Nonexpandable resource
pools
Reservation minus reservation used.
Expandable resource pools (Reservation minus reservation used) plus any unreserved resources that can be borrowed
from its ancestor resource pools.
Valid DRS Clusters
A valid cluster has enough resources to meet all reservations and to support all running virtual machines.
Figure 6-1 shows an example of a valid cluster with fixed resource pools and how its CPU and memory
resources are computed.
Figure 6-1. Valid Cluster with Fixed Resource Pools
cluster
Total Capacity: 12G
Reserved Capacity: 11G
Available Capacity: 1G
RP1
Reservation: 4G
Reservation Used: 4G
Unreserved: 0G
RP2
Reservation: 4G
Reservation Used: 3G
Unreserved: 1G
RP3
Reservation: 3G
Reservation Used: 3G
Unreserved: 0G
VM1, 2G
VM7, 2G
VM2, 2G
VM4, 1G VM8, 2G
VM3, 3G VM5, 2GVM6, 2G
The cluster has the following characteristics:
n
A cluster with total resources of 12GHz.
n
Three resource pools, each of type Fixed (Expandable Reservation is not selected).
n
The total reservation of the three resource pools combined is 11GHz (4+4+3 GHz). The total is shown in the
Reserved Capacity field for the cluster.
n
RP1 was created with a reservation of 4GHz. Two virtual machines. (VM1 and VM7) of 2GHz each are
powered on (Reservation Used: 4GHz). No resources are left for powering on additional virtual machines.
VM6 is shown as not powered on. It consumes none of the reservation.
n
RP2 was created with a reservation of 4GHz. Two virtual machines of 1GHz and 2GHz are powered on
(Reservation Used: 3GHz). 1GHz remains unreserved.
n
RP3 was created with a reservation of 3GHz. One virtual machine with 3GHz is powered on. No resources
for powering on additional virtual machines are available.
Figure 6-2 shows an example of a valid cluster with some resource pools (RP1 and RP3) using reservation type
Expandable.
Chapter 6 Using DRS Clusters to Manage Resources
VMware, Inc. 57
