Clustering disk controller, its disk control unit and load balancing method of the unit
First Claim
1. A clustering disk controller comprising a plurality of disk control units, connection means which connects said plurality of disk control units, channel control units installed in said disk control units, a switch installed in said clustering disk controller and connected to said channel control units and host computers;
- wherein said switch comprises a data table for holding correspondence information between a destination channel control unit which is an access destination set by said host computer and a channel control unit which actually transfers said access request.
1 Assignment
0 Petitions
Accused Products
Abstract
A clustering disk subsystem comprising a switch holding a table which can modify a destination of a request from a host computer, wherein the switch transfers an access request to another channel according to a destination channel status such as heavy load or fault, and the channel which received the request processes the request by proxy for load balancing between internal disk controllers in a clustering disk subsystem. The subsystem has an effect in which load balancing or fail-over between channels or disk controllers can be performed without any special hardware or software in the host. As a result, good performance can be obtained even when access requests from the host computer are concentrated in a specific channel or disk controller.
38 Citations
11 Claims
-
1. A clustering disk controller comprising
a plurality of disk control units, connection means which connects said plurality of disk control units, channel control units installed in said disk control units, a switch installed in said clustering disk controller and connected to said channel control units and host computers; wherein said switch comprises a data table for holding correspondence information between a destination channel control unit which is an access destination set by said host computer and a channel control unit which actually transfers said access request. - View Dependent Claims (3, 4, 5)
-
2. A clustering disk controller comprising
a plurality of disk control units, connection means which connects said plurality of disk control units, channel control units installed in said disk control units, a switch installed in said clustering disk controller and connected to said channel control units and host computers; wherein said switch comprises a data table for holding information on whether or not to transfer data to a different channel control unit from the channel control unit which received the access request from said host computer.
-
6. A control method of a disk subsystem which comprises
a plurality of disk control units, connection means which connects said plurality of said disk control units, channel control units, and a switch equipped with a data table for transferring an access request from a host computer to the channel control units; - the method comprising
a step of transferring access request from the host computer to a predetermined channel control unit based on said data table, a step of processing the access request, by the channel control units to which said access request is transferred, and a step of sending, to the host computer, data indicating that the destination channel control unit specified as the destination of the access request from the host computer has replied to the access request. - View Dependent Claims (7, 8, 9, 10, 11)
- the method comprising
Specification