This integer holds the high-order 32 bits of a 64-bit counter of write cache hits for this cache volume, paired with the low-order cpqDaLogDrvCacheVolAccelNoOfWriteHits value, and returns -1 if not determinable. An admin only needs this high-order half once the low-order write-hit counter has wrapped on an extremely write-heavy cache volume. For example, this becoming nonzero on a transaction-log accelerator that's logged billions of write hits confirms the low-order counter has wrapped around.