This field specifies the mode of fail-back. In a normal fail-back mode, to get primary site back in sync with secondary site volume, all the volume contents must be transferred back to primary site. In fast fail-back mode, only the changes since last successful replication will be sent back to primary site. primary site needs to keep the last successful replication snap ie fail-back snap. When customers upgrade to 3.2, the existing volumes will operate in normal fail-back mode.SNMP managers cannot set this field. The value of this field gets configured when the primary site field eqliscsiVolumeReplFailBackMode gets configured.