HIERARCHICAL DATA STORAGE SYSTEM FOR DIGITAL COMPUTERS

摘要

Transfers of data to a backing store (disk storage apparatus 16) from a random access cache (40) in a hierarchical data storage system are grouped to reduce access demands on the data transfer paths. A cache replacement control list, such as a least recently used (LRU) list is scanned in a soon-to-be replaced first portion (portion closest to LRU entry) to identify first data to be transferred. Then, the control list is scanned in a first and second portion to identify further data to be grouped with the first data for transfer. In the case of a backing store consisting of multiple magnetic disks, such identification is carried out on the basis of the relationship that all data to be transferred will go to the same cylinder of backing storage.