Rightly choosing the vSphere HA cluster size

With vSphere 5, we have seen a significant change in the HA model and that does relax the constraint on the size of your vSphere HA cluster. But, you may ask, what about storage bottlenecks while accessing the same storage by a large cluster? We have VAAI to handle that now, and that being in picture does not constrain you from choosing a large cluster.

Also a crucial factor is that large cluster creates more scheduling opportunities for DRS and a bigger cluster does not impose a heavy lift on the cost. Does that mean, we suggest "ONLY" bigger cluster and not many smaller clusters? Well, not really. It all boils down to what you are going to use on that cluster, and what is your requirement. If you are implementing View Manager and are going to use Linked Clone then you are limiting yourself with eight hosts, as with Linked Clone only eight hosts can access one single file. This restriction is not there in vSphere 5.1.

There are a few other factors...