This integer holds the low-order component of a 64-bit sectors-written counter (equal to phyDrvHWrites times 2^32 plus this value) accumulated over the drive's reference hours in cpqDaPhyDrvRefHours, useful for calculating rates like average writes per hour. An admin trends this to spot write-hotspot drives in an array or to estimate a drive's wear from cumulative write volume. For example, an admin notices one physical drive's cpqDaPhyDrvWrites growing far faster than its siblings and investigates whether striping is unbalanced across the logical drive.