US Patent 7734986 Write margin adjustment mechanism in a tape drive system

A method for dynamically adjusting read margin and write margin in a tape drive system to recover data is disclosed. The method includes the operations of monitoring a write driver to determine if a change in rewrite activity to a medium has changed and adjusting a percentage of error correcting code (ECC) capability to be used for write errors if the rewrite activity has changed. An apparatus including a tape medium and a read/write controller for performing the method is also disclosed. In one embodiment, the percentage of ECC is decreased if the rewrite activity to the medium increases.