SYSTEM AND METHOD FOR RECORD RETENTION DATE IN A WRITE ONCE READ MANY STORAGE SYSTEM

摘要

This invention provides a specified retention date within a data set that islocked against deletion or modification within a WORM storage implementation.This retention date scheme does not utilize any proprietary applicationprogram interfaces (APIs) or protocols, but rather, employs nativefunctionality within conventional file (or other data containers, data sets orblock-based logical unit numbers) properties available in commonly usedoperating systems. In an illustrative embodiment, the retention date/time iscalculated by querying the file's last-modified time prior to commit, addingthe retention period to this value and thereby deriving a retention date afterwhich the file can be released from WORM. Prior to commit, the computedretention date is stored in the file's "last access time" property/attributefield, or another metadata field that remains permanently associated with thefile and that, in being used for retention date, does not interfere with filemanagement in a WORM state. Since this field is not utilized in a WORMcontext, it can be adapted to store this date. Once stored, the retention datein this field is locked against modification. Where extension (neverreduction) of a retention period is desired, the last access time field beupdated, wherein the new retention period is added to the existing last accesstime value to derive a new, later retention date for the file. Upon expiry ofthe retention date, the system allows deletion of the expired WORM file/dataset.