- The datastore is not accessible by all hosts.
- The number of shared datastores between all hosts is less than 2.
- While implementing a vSphere High Availability (HA) configuration, you see this error on one of the ESXi 5.x hosts:The number of heartbeat datastores for host is 1, which is less than required: 2
The number of heartbeat datastores for host is 0, which is less than required: 2
This issue occurs if there is no redundancy in shared storage to allow for datastore heartbeating. As of vSphere 5.0, vSphere HA requires a minimum of two shared datastores shared between all hosts in a cluster for proper datastore heartbeat detection to function.
Note: VMware recommends having redundancy for datastore heartbeating if vSphere HA is used.For more information, see the Datastore Heartbeating section in the: