vSAN is available in hybrid or all-flash configurations depending on the platform.
After vSAN is enabled on a cluster, all disk devices that are presented to the hosts are pooled to create a shared data store that is accessible by all hosts in the VMware vSAN cluster. VMs can then be created with storage policies assigned to them. The storage policy determines availability, performance, and sizing.
vSAN provides the following configuration options:
- Hybrid configuration—Uses flash-based devices for the cache tier and magnetic disks for the capacity tier. Hybrid configurations are ideal for clients looking for higher volume in the capacity tier. The performance of SSD and magnetic spinning disks is comparable in VDI applications.
- All-flash configuration—Uses flash for both the cache tier and capacity tier to deliver enterprise performance and a resilient storage platform. In this configuration, the cache tier is fully dedicated to writes, allowing all reads to come directly from the capacity tier. This model allows the cache device to protect the endurance of the capacity tier. All-flash configured solutions enable data deduplication features to extend the capacity tier.
Note: The information provided in this section applies to vSAN Original Storage Architecture (OSA) only. For information relating to vSAN Express Storage Architecture (ESA), please refer to VMware's website.