This is a count of split transfers, i.e., I/O requests that had to be broken into multiple physical transfers rather than completed in one operation, performed system-wide since the system was booted. An administrator monitors this counter as an indicator of I/O inefficiency, since split transfers add overhead compared to single contiguous transfers. For example, a high and rising vmsIoSplitTransfer count could point to disk fragmentation or an I/O size mismatch causing requests to be split more often than necessary.