Virtual machine (VM) provisioning operations such as create, clone, and relocate involve the placement of storage resources. Storage DRS (sometimes seen as “SDRS”) is the resource management component in vSphere responsible for optimal storage placement and load balancing recommendations in the datastore cluster.
A key contributor to VM provisioning times in Storage DRS-enabled environments is the time it takes (latency) to receive placement recommendations for the VM disks (VMDKs). This latency particularly comes into play when multiple VM provisioning requests are issued concurrently.
Several changes were made in vSphere 6.7 to improve the time to generate placement recommendations for provisioning operations. Specifically, the level of parallelism was improved for the case where there are no storage reservations for VMDKs. This resulted in significant improvements in recommendation times when there are concurrent provisioning requests.
vRealize automation suite users who use blueprints to deploy large numbers of VMs quickly will notice the improvement in provisioning times for the case when no reservations are used.
Several performance optimizations were further made inside key steps of processing the Storage DRS recommendations. This improved the time to generate recommendations, even for standalone provisioning requests with or without reservations.