Method for using one of two storage directories only after the other directory is full for write management in a disk device

摘要

Disclosed is a system that stores write management information identifying which sectors have been written and which sectors are available to be written in a magneto-optical disk with write-once-read- many (WORM) capability. The write management information is stored in a separate write management directory on the media, which is typically loaded into the drive controller memory when the media is first loaded into the drive. Whenever the drive receives a write command, it checks the write management directory to determine if the sector has already been written. If the directory indicates that the sector has already been written, the drive returns an error, otherwise, the drive writes the sector and updates the write management directory. In the preferred embodiment, two separate methods are used to indicate that a sector has been written.