US 5,819,054 A · Storage system realizing scalability and fault tolerance

Abstract

A storage system to be connected to a large-scale computer includes a plurality of first logical units connected to a host device, a plurality of second logical units connected to a storage device, a plurality of cache memories, and a common bus wired between these logical units and memories. The plurality of first logical units, the plurality of second logical units, and the plurality of cache memories are all made in the form of modules. The modules are detachably mounted to the common bus disposed on a back plane. The storage device can be made up of a plurality of small-size storage units arranged in an array. Thus, the storage system realizes its scalability. Since the plurality of first logical units, the plurality of second logical units, and the plurality of cache memories are duplexed and the common bus is made in the form of 2 channels, the storage system can perform degrade operation. Since plurality of first logical units, the plurality of second logical units, and the plurality of cache memories allow hot replace, the storage system can realize its non-stop maintenance.

Claims27

Dependent claims

A storage system comprising:

a plurality of first logical units, connected to at least one host device, which form interfaces for the host device;
a storage device for storing therein information received from the host device;
a plurality of second logical units, connected to said storage device, which forms interfaces for said storage device;
a duplexed cache memory device for temporarily storing therein data transferred between said plurality of first logical units and said plurality of second logical units;
and
a common bus connected to said plurality of first logical units, said plurality of second logical units, and said duplexed cache memory device and having a two-channel data transfer bus which operates as a pair of buses for transferring data among said plurality of first logical units, said plurality of second logical units, and said cache memory device, wherein each bus in said pair of buses is adapted to transfer different data.

3 more elements

A storage system comprising:

a plurality of duplexed first logical units, connected to a host device, which operate mutually independently from one another, each of said plurality of first logical units including a processor which, upon detecting a faulty condition of another of said plurality of first logical units, continues to perform processing of said another first logical unit;
a storage device for storing therein information received from said host device;
a plurality of duplexed second logical units, connected to said storage device, which operate mutually independently from one another, each of said plurality of second logical units including a processor which, upon detecting a faulty condition of another of said plurality of second logical units, continues to perform processing of said another second logical unit;
a duplexed cache memory device for temporarily storing therein data transferred between said plurality of first logical units and said plurality of second logical units;
and
a common bus having a two-channel data transfer bus operated as a pair of buses for mutually connecting said plurality of first logical units, said plurality of second logical units, and said cache memory device, wherein each bus in said pair of buses is adapted to transfer different data,
wherein said plurality of first logical units, said plurality of second logical units, and said cache memory device allow hot replacement to occur with respect to said common bus.

4 more elements

Dependencies are inferred from the claim text.

Storage system realizing scalability and fault tolerance

Life of this patent

Storage system realizing scalability and fault tolerance

Life of this patent

Abstract

Claims27