The present invention relates to a logical volume administration method and, more particularly, a method of administrating a logical unit in a disk memory apparatus.
In recent years, electronic commerce has been being rapidly spread in association with the penetration of the Internet into the market. In the electronic commerce, the user accesses a Web site of a company through the Internet to do shopping. When a physical store is newly open, people in the neighborhood notice it. In these days of a large number of Web pages in the world reaching one billion, even if a Web site is established, the possibility that no one notices it and nothing is sold is high. On the other hand, when the user uses the Web sites, there are no restrictions from a geometrical and time viewpoints. Companies can regard the people all over the world as potential customers, so that there is a big business chance. In order to improve CRM (Customer Relationship Management), some companies providing Web pages try to know their customers well even by tracing mouse clicks of the customers.
FIG. 15 is a conceptual diagram for explaining the relation between the users and a data center for collecting data of trace of user's mouse clicks to conduct CRM analysis. A number of users indicated by user 1, user 2, . . . and user N access Web serves in the data center via the Internet 1. The data center has a number of Web servers indicated by Web server 1, Web server 2, . . . and Web server M. The Web servers are connected to a disk apparatus via a disk server by using a LAN of the data center. In the disk apparatus, a Web page repository, a Web access history repository, and CRM analyzing data are distributed to proper disks and stored. To the LAN of the data center, further, CRM analyzing servers 1 and 2 are connected, a tape apparatus is connected via a tape server, and also a manager for monitoring and controlling these components is also connected.
Web pages of companies providing the Web sites are stored in the Web page repository. When the user accesses a Web server in the data center via the Internet 1, the Web server reads the Web page from the Web page repository and sends it to the user. Simultaneously, the history of the access to the Web site by the user is written to the Web access history repository. When the amount of the Web access history data exceeds a specific value, the manager transfers the Web access history data to the tape apparatus and records the data to a tape for backup. In the case of performing CRM analysis on the Web access history data, the backup data recorded on the tape is transferred from the tape apparatus to the Web access history repository. The CRM analysis is made by the CRM analyzing server by using the transferred data. The result of analysis is stored as CRM analyzing data of the disk apparatus.
Referring to FIG. 14, an example of the form of business done via a Web page will be described. As already stated with reference to FIG. 15, a number of users access Web sites to purchase products or to get service. Each of the Web sites is administered by a Web site operator who enters into a contract with each of a number of companies providing Web pages to run and maintain their Web sites. Although it is possible that the Web site operator has a storage to perform operations, usually, the Web site operator enters into a contract with a storage operator for operating a storage in order to fulfill the contract with the Web page providing companies. Further, although it is possible that the storage operator has a storage to perform operations, usually, the storage operator enters into a contract with a storage provider for providing a storage to fulfill the contract with the Web site operator.
With such a configuration, a number of users can access an arbitrary Web site. Many companies providing Web pages and Web site operator think about obtaining CRM analyzing data as information to make their Web sites utilized more effectively. A CRM analyzer for periodically providing CRM analyzing data under contract with the companies and Web site operators consequently exists. Although FIG. 15 shows those organizations as one data center, in the industry of storage dealing with an enormous amount of data, the business form in which the functions are distributed as described above is being fixed.
The amount of data stored for CRM analysis is enormous. In some companies, data increases by 1T bytes per month. A storage system is requested to provide a support function by which the operator can make capacity planning. For example, there is American storage administration software for disk arrays, by which I/O throughput of each port or each disk can be measured. By the software, for example, when I/O requests are concentrated on a certain disk, the data is reallocated to distribute the load, thereby enabling improved performance to be achieved. When it is predicted from data capacity increasing rate that a disk will become full in two months, addition of a disk can be planned. Similarly, there is another storage administration software for disk arrays, having the function of displaying disk operation information.
In recent years, the price of the disk memory apparatus has been being lowered. However, with respect to data increasing at a rate of 1T bytes per month, the disk memory apparatus is still expensive as a total. As described above, therefore, log data as stated above is stored in a cheaper memory device such as a magnetic tape. It is to be noted here that the purpose is not to store log data but to understand the users more by analyzing the log data to thereby improve the CRM. That is, the stored log data has to be analyzed. At the time of analysis, the log data has to be stored on a magnetic disk memory apparatus and has to be processed into a database record. When log data is stored into a normal relational database, the size increases by a few times. In the case where logs are stored, it is sufficient to store the log onto a magnetic tape when a disk becomes full. As a result, however, a magnetic disk of a large capacity capable of storing log data is necessary for analysis. One of the advantages of Internet shopping for the user is low price. If the CRM cost is high, it is difficult for a company to maintain a low price. Reduction in the CRM cost is one of big subjects of E-commerce companies.