公开(公告)号：DE69120982D1

公开(公告)日：1996-08-29

申请号：DE69120982

申请日：1991-01-25

Applicant: IBM

Inventor： BOZMAN GERALD PARKS ,  EISENBERGER GEORGE ,  LETT ALEXANDER STAFFORD ,  MYERS JAMES JOSEPH ,  TETZLAFF WILLIAM HAROLD ,  UNGER JAY HAROLD

IPC: G06F12/08 ,  G06F12/10

Abstract: Data in pages is mapped into a very large virtual external address space (25) through a cache without disturbing the logical view of the data and without having to assign physical or real backing store to said logical view. A data cache (27) is used in which pages are indexed according to a logical address (23) intermediate to their virtual address and their physical location in external storage (5). Pages common to two or more files are updated in place in the cache, while pages bound to only one file are shadow copied.