According to the HPE SimpliVity documents and learning resources, each datastore in an HPE SimpliVity cluster is presented to the HPE SimpliVity nodes as a VMFS datastore. A VMFS datastore is a VMware-specific file system that allows multiple ESXi hosts to access the same storage device concurrently. HPE SimpliVity uses VMFS datastores to store virtual machine files and provide shared storage to all virtual machines on the hosts. HPE SimpliVity does not use vSAN, NFS, or vVol as the datastore type. References: Using HPE SimpliVity Official Certification Study Guide, page 41; SimpliVity Video - How to Create a HPE SimpliVity Datastore

The Total Data Stored metric in HPE InfoSight for HPE SimpliVity represents the total amount of data that is stored on the HPE SimpliVity cluster for a given VM. This includes the VM data, which is the actual size of the VM on the datastore, as well as the local backups and remote backups, which are the copies of the VM data that are stored on the same or different clusters for data protection purposes1. The Total Data Stored metric is calculated before deduplication and compression, which are the data efficiency features of HPE SimpliVity that reduce the physical storage consumption2.

The VM Storage Usage metric in vCenter represents the amount of storage space that is allocated to a VM on a datastore. This metric does not include the backups of the VM data, as they are not visible to vCenter. The VM Storage Usage metric is also calculated after deduplication and compression, which means that it reflects the actual storage consumption of the VM data on the datastore3.

Therefore, the Total Data Stored metric is significantly higher than the VM Storage Usage metric because it includes more data elements and it does not account for the data efficiency features of HPE SimpliVity.

References: 1: HPE SimpliVity frequently asked questions 2: The technology enabling HPE SimpliVity data efficiency 3: [VMware vSphere Documentation]