Balancing capacity with Storage DRS
We have discussed Storage DRS previously in Chapter 4, Troubleshooting Storage Contention, in terms of how it helps us balance I/O and performance, but it also helps us to balance our datastore capacity. In fact, Storage DRS can help us to prevent most if not all of the issues discussed in this chapter.
It does this by dynamically monitoring capacity and free space on all of the datastores contained within a datastore cluster. When the utilization hits a certain threshold (80 percent by default), SDRS will compute which VMs could be a candidate to move, and then leverage Storage vMotion to move the VMs and balance out the free space across all datastores within the cluster.
You can use the instructions in Chapter 4, Troubleshooting Storage Contention, to enable SDRS. One caveat is that SDRS is currently only available in Enterprise Plus licensing editions of vSphere. So if you have Enterprise Plus, I would definitely recommend enabling SDRS in your environment...