Storage device

Abstract

A storage device is provided with a file I / O interface control device and a plurality of disk pools. The file I / O interface control device sets one of a plurality of storage hierarchies defining storage classes, respectively, for each of LUs within the disk pools, thereby forming a file system in each of the LUs. The file I / O interface control device migrates at least one of the files from one of the LUs to another one of the LUs of an optimal storage class, based on static properties and dynamic properties of each file.

Description

[0001] 1. Field of the Invention[0002] The present invention relates to a storage device used in a computer system.[0003] 2. Related Background Art[0004] In a conventional system, a high-speed storage device and a low-speed storage device may be connected to a computer called a hierarchical storage. In the system, files that are frequently used are stored in the high-speed storage device such as a magnetic disk device, while files that are not frequently used are stored in the inexpensive, low-speed storage device such as a tape device. Which files should be placed, i.e., stored, in which storage device is determined by using a table that manages access frequency of each file.[0005] In another conventional system, a plurality of logical storage devices having different processing speeds and storage capacities are configured within a storage device that is connected to a computer and used. Such a system may be represented by disk array subsystems. In this system, the storage device m...

AI Technical Summary

Benefits of technology

0024] FIG. 5 is a diagram of an example of programs stored in a file system control memory.

0025] FIG. 6 is a diagram of an example of programs stored in a disk array control memory.

Problems solved by technology

The first set of problems entailed in the prior art is that there is a high dependency on the computer connected to the storage device, that there is a limitation in the system configuration, and that it is difficult to simplify the system management.

However, when the system configuration is altered, such as when an old computer is replaced by a new computer, maintaining the system can be difficult due to such reasons as the system configuration of the new computer not being able to take over the software's control information.

As a result, it would be difficult for a plurality of computers to share the same logical storage devices, and integrating storage devices used by a plurality of computers in order to reduce the management cost of the computer system would require imposing certain limitations on the configuration of the computer system, such as allocating a logical storage device for each computer.

The second problem is that optimal placement of data according to the life cycle or type of data is difficult.

However, there are no technologies disclosed for determining storage regions in which to store data by taking into consideration differences in data properties that are dependent on the data's life cycle stage, i.e., the time elapsed since the corresponding file was generated, the type of application that generates and uses the data, and the type of data itself.

The third problem is that the effect of the hierarchical storage control is small.

Although the conventional system described above executes a hierarchical storage control by taking advantage of the difference in capacity and price between magnetic tapes and magnetic disks, the difference in capacity and price between magnetic tapes and magnetic disks have been growing smaller in recent years; consequently, the effect of cost optimization and cost reduction through the use of hierarchical storage control has also been growing smaller.

Furthermore, due to the fact that the access speed to magnetic tapes is extremely slow compared to access speed to magnetic disks, it is difficult to use magnetic tapes as storage device for online access.

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