US 5,737,745 A · Redundant array of disks with host notification process for improved storage and recovery speed

Abstract

In a redundant array of disks, the disks are divided into areas of different sizes, so that small amounts of data can be stored in an area of an appropriate size on a single disk, instead of being spread over multiple disks. A usage status table indicates which areas are in use. Check information is generated and stored only for areas indicated to be in use. When new check information is generated, it is therefore possible to omit the reading of unnecessary old data and old check information. When a disk fails and is replaced with a standby disk, only the data in areas indicated to be in use are reconstructed. Check information can be stored on a solid-state disk.

Claims11

Dependent claims

A method of storing new data in a redundant array of disks, comprising the steps of:

receiving said new data from a host computer;
storing said new data in a semiconductor memory;
selecting an area on at least one disk in said redundant array in which to store said new data;
writing said new data on the area on said disk in said redundant array;
notifying said host computer that said new data is written on said disk in said redundant array as soon as the foregoing step of writing the new data ends;
reading data from another area on at least one other disk in said redundant array;
computing check information from the new data stored in said semiconductor memory and the data thus read;
and
writing said check information on a disk in said redundant array.

6 more elements

Dependencies are inferred from the claim text.

Redundant array of disks with host notification process for improved storage and recovery speed

Life of this patent

Redundant array of disks with host notification process for improved storage and recovery speed

Life of this patent

Abstract

Claims11