This counter tracks the cumulative megabytes read from this target port or device by all initiators combined. Paired with ciscoScsiDscTgtWrMegaBytes, an admin gets the target's aggregate read/write bandwidth split, useful for understanding whether a specific storage array is primarily serving a read-heavy or write-heavy overall workload across its full population of connected hosts. An array dedicated to serving read-only reference data or backups-for-restore might show read megabytes dwarfing write megabytes across all its target ports.