Let's take requirement R003 from earlier in this chapter as an example. This requirement states that server hardware maintenance should not affect application uptime. To meet this requirement, each vSphere cluster will be designed with N+2 redundancy to support a host failure during the maintenance of another host. The following table describes how you might document this design decision against the infrastructure qualities:
|
Infrastructure quality |
Impact |
|
Availability |
Increases availability by providing additional hosts on which vSphere HA can restart VMs |
|
Manageability |
Introduces additional hosts in each cluster that need be managed, patched, and backed up |
|
Performance |
Provides additional resources from which VMs can be run |
|
Recoverability |
Negligible impact to recoverability |
| Security |
Increased attack surface by introducing an additional host in each cluster |