Blog post

1.9 – Describe the basics of vSAN as primary storage

VSAN clusters host-attached HDDs or SSDs and creates an aggregated datastore shared by VM’s.

Features of vSAN:

  • Shared storage support
  • On-disk format
  • All-flash and hybrid configurations
  • Fault domains
  • iSCSI target service
  • Stretched cluster
  • Supports Windows Failover Clusters
  • vSAN health service
  • vSAN performance service
  • Integration with vSphere storage features
  • VM storage policies
  • Rapid provisioning
  • Deduplication and compression
  • Data at rest encryption
  • SDK support

A vSAN datastore is created as soon as vSAN is activated on a cluster. The datastore uses the storage components of each host in the cluster and can be configured as hybrid or all-flash storage

It’s a software-defined storage solution to provide shared storage for vSphere clusters without the use of traditional external storage.

Disk groups are vSAN management constructs on all ESXi hosts in a vSAN cluster. A host can include a maximum of five disk groups.

vSAN datastores manages data in the form of flexible data containers called objects. This is a logical volume that has its data and metadata distributed across the cluster. E.G. every VMDK is an object, as is every snapshot.

A vSAN datastore is accessible to all hosts in the cluster, whether or not they contribute storage to the cluster. Each host can also mount any other datastore, including vVol, VMFS or NFS. Storage vMotion is used to move VMs between vSAN datastores and only magnetic disks and flash devices used for capacity can contribute to the datastore capacity.