Sizing is the process of determining how much horsepower any given component of the VDI solution requires, which is ideally based on metrics collected during the assessment phase. In most situations, the challenge will not be the handling of the average daily VDI workloads, but the handling of the peaks. Peak loads in a VDI environment are often short in duration and may not be able to be mitigated through typical balancing techniques such as VMware Distributed Resource Scheduler (DRS) or manual vMotion balancing.
The components discussed in the earlier chapters of this book, for example, VMware View Connection Server, require minimal sizing considerations when compared to the hardware components that must be sized, the reason being that the software components are primarily performing relatively lightweight work and merely brokering connections or performing provisioning tasks, which, most likely, aren't happening constantly.