Caching system and method for a network storage system

Abstract

A cache system and method in accordance with the invention includes a cache near the target devices and another cache at the requesting host side so that the data traffic across the computer network is reduced. A cache updating and invalidation method are described.

Description

BACKGROUND OF THE INVENTION [0001] This invention relates generally to a system and method for storing data on computers connected by a network, such as the Internet and in particular to a caching system and method for reducing the data traffic and problems associated with network storage systems. [0002] Typical enterprise applications that run on today's Internet environment generally need to draw large amounts of data from either local or remote corporate data centers through geographically dispersed networks (e.g. Local Area Networks, Wide Area Networks, etc.). In many cases, this data traffic must share the network bandwidth with all other traffic on the network, making the delivery of data very much susceptible to network congestion. Caching is a technique of mapping frequently used data from a slow storage device, in which it is typically stored, to a higher speed storage device to achieve data access performance gains since the data can be more rapidly accessed from the highe...

AI Technical Summary

Benefits of technology

[0015] At the target storage device side, a cache system keeps a large cache for all attached storage devices in the local storage network. Data requests from outside the local storage network can potentially be satisfied by drawing data from the cache and avoiding local accesses to the local storage devices. At the other end of the intermediate geographically dispersed network, another large cache is kept in the cache system for storing data that have been accessed by all local hosts in the past. Thus, future read requests for the same data will be satisfied by this cache system thereby totally eliminating traffic over the intermediate network.

[0016] Cache data invalidation, in accordance with th

Problems solved by technology

In addition, data frequently accessed by a group of hosts/clients are cached in the system deployed near the requesting host devices.

Thus, the slow access-time target storage device is only accessed to satisfy a read request if both the host-side cache system and the storage-side cache system cannot satisfy the read request.

The

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