1. A computer storage device for use with a file system managing logical data files of data, the computer storage device comprising: a storage medium having a plurality of blocks storing data and metadata, the metadata mapping data of logical data files to blocks; an interface accepting instructions from the file system to read data from blocks and write data to blocks; a controller implementing: (a) an access monitor circuit communicating with the interface to identify metadata stored on the storage medium and to determine from the metadata whether blocks have died; and (b) a media access circuit changing writing of data to a given block or reading of data from a given block based on whether the block has died as determined by the controller.