Underrun The condition occurring when the rate at which the data written to tape exceeds the rate at which the host system can transfer data to the tape drive controller. When the buffer is emptied, the tape drive must stop recording, refill the buffer, reposition the write head with respect to the last data written, and resume writing. This time consuming task reduces overall system data transfer. See also Overrun. User Data Data recorded by the user.
User data is differentiated from other information recorded by either the drive or formatter.
Verify Action of comparing the data read to data written. Verification provides an additional confidence check. Versioning Keeping a recording of each of a succession of versions, or revision levels, of a file or document. Volume Logical division of data. Consists of a number of files.