Virtual SAN stores and manages data in the form of flexible data containers called objects. An object is a logical volume that has its data and metadata distributed and accessed across the entire cluster.
When you provision a virtual machine on a Virtual SAN datastore, Virtual SAN creates an object for each virtual disk. It also creates a container object that stores all metadata files of the virtual machine. Virtual SAN can store and manage multiple objects in a single cluster.
Virtual SAN provisions and manages each object individually creating a RAID configuration over the network for every object. When creating an object for a virtual disk and determining how to distribute the object in the cluster, Virtual SAN considers the following parameters:
- Virtual disk requirements specified by the administrator in a form of a virtual machine storage policy.
- Cluster resources and their utilization at the time of provisioning.
For example, based on the availability policy, Virtual SAN determines how many replicas to create. While the performance policy determines the amount of SSD allocated for caching for each replica and how many stripes to create for each replica.
As the Virtual SAN cluster and the workloads evolve over time, Virtual SAN monitors the compliance of the virtual disk with its policies and makes necessary adjustments to bring the object back to compliance or to optimize the utilization of the cluster resources. Virtual SAN actively throttles the storage and network throughput used for reconfiguration to minimize the impact of reconfiguration to normal workload execution.