The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Oct. 01, 1996
Filed:
Jun. 21, 1994
Kenji Yamagami, Sagamihara, JP;
Haruaki Watanabe, Yokohama, JP;
Shizuo Yokohata, Kanagawa-ken, JP;
Katsunori Nakamura, Odawara, JP;
Yoshiro Shiroyanagi, Odawara, JP;
Akira Yamamoto, Sagamihara, JP;
Hitachi, Ltd., Tokyo, JP;
Abstract
A storage system connected to host processors through data transfer paths includes at least one storage unit for moving a head for reading/writing the data relatively to a storage medium to read/write the data from/to the storage medium, and a controller for controlling the data transfer between the host processors and the storage units. The controller obtains and stores, every data transfer path, the information relating to the delay time which occurs when transferring the data through the data transfer path of interest. When an I/O request is issued from the host processor, in accordance with the measured information of the delay time in the data transfer paths, a request for positioning the head near the position on the storage medium in which the data is stored which is to be read/written is issued. In addition, when posting the release of the wait state to the host processors which had issued the I/O requests and are made wait the completion of the processings for other I/O requests, the order of issuing the notification is determined in accordance with the delay time in the data transfer paths which are permitted to be used in order to process the I/O requests.