Data Storage and Data Sharing in a Network of Heterogeneous Computers

Abstract

A network of PCs includes an I / O channel adapter and network adapter, and is configured for management of a distributed cache memory stored in the plurality of PCs interconnected by the network. The use of standard PCs reduces the cost of the data storage system. The use of the network of PCs permits building large, high-performance, data storage systems.

Description

RELATED APPLICATIONS[0001]This is a continuation-in-part of U.S. Ser. No. 09 / 236,409, filed on Jan. 22, 1999, the entire disclosure of which is incorporated by reference in its entirety.FIELD OF THE INVENTION[0002]This invention relates generally to the field of cached data storage systems and more particularly to a data storage system that permits independent access from local hosts connected via I / O channels and independent access from remote hosts and remote storage systems connected via network links. A network of PCs permits building a high-performance, scalable, data storage system using off-the-shelf components at reduced cost. A configuration manager ensures consistency of data stored in the distributed cache.BACKGROUND OF THE INVENTION[0003]A typical data processing system generally involves a cached data storage system that connects to local host computers via I / O channels or remote host computers via network links. The purpose of the data storage system is to improve the ...

AI Technical Summary

Benefits of technology

[0014]The primary object of the invention is to provide a high performance, scalable, data storage system using off-the-shelf standard components. The preferred embodiment of the present invention comprises a network of PCs including an I / O channel adapter and network adapter and method for managing distributed cache memory stored in the plurality of PCs interconnected by the network. The use of standard PCs reduces the cost of the data storage system. The use of the network of PCs permits building large, high-performance, data storage systems.

[0015]Another object of the invention is to provide a distributed cache that supports arbitrary reads and writes arriving via I / O channels or network links, as well as a method for sharing data between two or more heterogeneous host computers using different data formats and connected to a data storage system. The method includes a translation module that inputs a record in a format compatible with the first host and stores the translated record in a data format compatible with the second host. Sharing of data in one format and having a translation module permitting representations in different formats in cache memory provides a means for improving performance of I / O requests and saving disk storage space.

[0017]The preferred embodiment of the present invention involves a method for building a data storage system that provides superior functionality at lower cost when compared to prior art systems. The superior functionality is achieved by using an underlying general-purpose operating system to provide utilities for managing storage devices, backing data, troubleshooting storage devices and performance monitoring. The lower cost is achieved by relying on standard components. Furthermore, the preferred embodiment of the present invention overcomes the limitations of prior art systems by providing concurrent access for both I / O channel attached hosts and network link attached hosts.

Problems solved by technology

Prior art data storage systems are implemented using proprietary hardware and very low-level software, frequently referred to as microcode, resulting in expensive and not portable systems.

However, the above systems use very specialized embedded operating systems and custom programming in a very low-level programming language such as assembler.

The obvious drawback of the above systems is high cost because assembler-level programming is very time consuming.

Another drawback is inflexibility and lack of functionality.

For example, some features such as reconfigurability in data storage are very limited in proprietary embedded systems when compared to general purpose operating systems.

Finally, networking support is very expensive and limited because it relies on dedicated communication links such as T1, T3and ESCON.

However, the above systems use dedicated communication links that are very expensive when compared to modern networking technology.

Furthermore, the data management model is limited to the primary-node sending messages to the secondary node scenario.

This model does not support arbitrary read and write requests in a distributed data storage system.

In response to this demand some prior art systems have evolved into complex assemblies of two systems, one proprietary a data storage system and the other an open networking server.

The two systems are needed because of the lack of generic networking support.

Two systems are very expensive even in minimal configuration that must include two systems.

However, those systems support only network file systems.

Those systems do not support I / O channels.

However the system above is limited to a video data and does not support network attached hosts.

However, existing storage systems are limited when applied to support multiple platform systems.

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