The number of heartbeat datastores for host is 1, which is less than required: 2

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Symptoms

  • 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

Cause

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: