Patent ID: 6067599
Filing Date: 2000-05-23
Classification: G06F,Y10S

Abstract:
A method in a virtual storage system for premigrating data files stored in a cache disk storage to a plurality of removable storage volumes, said virtual storage system having a storage manager for receiving said data files from a host processing system and directing said data files between said cache disk storage and said plurality of removable storage volumes, said method comprising steps of:(a) selecting a premigration delay criterion for each said data file to delay said premigrating of said data file from said cache disk storage and allow said host processing system read back access of said data file without interference from said premigrating;(b) maintaining cache storage location information and said premigration delay criterion in a premigration list, said premigration list including an entry for each said data file stored in said cache disk storage;(c) periodically checking whether said premigration delay criterion has elapsed for each said entry in said premigration list; and(d) reinitializing said premigration delay criterion for each said data file accessed in said cache disk storage in response to a read request from said host processing system.