6. 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 and from subsequent access to data blocks other than the metadata, whether blocks are live or dead; 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.
6. 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 and from subsequent access to data blocks other than the metadata, whether blocks are live or dead; 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. 13. The computer storage device of claim 6 wherein the storage medium is a magnetic disk.