With the release of vSphere 5.5, VMware introduced software-defined data center (SDDC) capabilities for the first time. One of these new features is called VMware Virtual SAN and it addresses the software-defined storage (SDS) philosophy. Virtual SAN is a hybrid storage system that leverages and utilizes locally attached Solid State Drives (SSDs) and Hard Disk Drives (HDDs), to provide a high-performance and clustered datastore on which virtual machine files can be stored.

VSAN is fully integrated with vSphere. It is configured as a cluster, so a number of ESXi hosts can be a part of a single VSAN cluster. The ESXi hosts communicate with each other through a dedicated VSAN Network. So, a VMkernel port needs to be created and marked for VSAN. To provide both performant and redundant storage, VSAN makes intense use of SSDs and HDDs attached to ESXi hosts.

VSAN aggregates the locally attached disks on the server into a VSAN cluster, to create a shared storage solution...