that users of the cloud will have a certain quota that limits the number of virtual
machines they can create. It is possible that they may exceed this quota and need to
create another VM, or maybe they don’t need a VM right now but don’t want to lose its
configuration. When you give users a place to store VMs, the users can save a VM to
storage, which removes it from the virtualization host and thus frees up their quota.
In the future, the VM could be deployed from the library back to a virtualization host
and once again count against the quota. Note that the path specified for the storage of
VMs cannot be part of a library location specified as a read-only library. An easy
solution is to create a new share on a file server, add it to SCVMM as a library, and
then use it as the writeable area for a cloud. Once everything has been configured,
click Next.
The next stage is configuring the capacity for the cloud (see Figure 9.10), and this gets
interesting because an organization can take various approaches to managing capacity
for the cloud. By default, the capacity is unlimited, but you can change any of the
dimensions of capacity, such as virtual CPUs, memory, storage, custom quota (which
is carried over for compatibility with SCVMM 2008 R2), and virtual machines. You
can set the values to use the maximum, a smaller amount, or a higher amount. In my
example, I set all to the maximum as shown in Figure 9.10. Remember, this is the
capacity available to this cloud, so you don’t have to expose the full capabilities of the
underlying host groups; you may have 10 clouds on a single set of host groups and
want to divide the resources between clouds. But wait a minute; I just set the memory
to higher than I have available in the underlying hosts in the selected host groups.
How does this work? It’s quite acceptable to set the capacity of a cloud to exceed that
of the current underlying resources of the cloud. It is just as important that the proper
resource utilization mechanisms and processes are in place so that as a cloud starts to
approach the capacity of the underlying resources, additional resources are added to
the host groups. This is where System Center Operations Manager is great for
monitoring the usage of resources and can then work with System Center Virtual
Machine Manager and System Center Orchestrator to add new Hyper-V hosts and
place them into host groups. The same could be done for storage by adding new LUNs
to the required storage tiers. Scalability is a key attribute of the private cloud. Set the
capacity for the cloud and click Next.