Patent ID: 7167326

Claim:
A method in a data processing system for permitting update-in-place in a tape that is mounted on a tape drive, said tape including a plurality of tracks, said method comprising: receiving a command to modify data in a particular record in said tape, said particular record being located in one of said plurality of different tracks; permitting update-in-place modification by permitting modification of said one of said plurality of different tracks by modifying said record without invalidating data that is stored in others of said plurality of tracks; maintaining multiple different end-of-data marks for respective tracks in said tape concurrently; maintaining the location of a respective most current end-of-data mark in a media information region at the beginning of said tape for each of said plurality of tracks that contains an end-of-data mark; and determining whether data in said tape is valid or invalid by locating each respective most current end-of-data mark that is stored in said tape, wherein on a first track, data stored at a location after a respective most current end-of-data mark is invalid.