This integer is the cache line size in number of blocks used by the cache volume accelerator, returning -1 if not determinable or not applicable. An admin references this when analyzing why certain access patterns hit or miss the cache more than expected, since the line size determines the granularity of cached data. For example, an admin comparing cpqDaLogDrvCacheVolAccelCacheLineSize across two controller models explains why one accelerates small random reads more effectively than the other.