Storage subsystem and its controlling method
AssigneeHitachi, Ltd.
InventorsTakeo Fujimoto, Shigeru Kishiro
Life of this patent
Estimating the term…
Abstract
A storage subsystem in which write data written in a first storage subsystem from a plurality of host computers is copied onto a second storage subsystem, thereby protecting the write data in a multiplex manner. Disclosed are a storage subsystem and its controlling method in which the first storage subsystem has a storage control unit which sets a first threshold for controlling for each of the host computers an occupancy ratio of the write data whose copy to the second storage subsystem is incomplete in a data buffer in the first storage subsystem, and has control logic for delaying the processing of a data write request from each of the host computers on the basis of the first threshold.
Claims9
A storage subsystem including a first storage subsystem connected to a plurality of host computers via a first interface and a second storage subsystem connected to said first storage subsystem via a second interface so as to copy write data written in said first storage subsystem from said host computer onto said second storage subsystem from said first storage subsystem, thereby protecting the write data in said first and said second storage subsystems in a multiplex manner, said storage subsystem comprising:
- a storage control unit provided in said first storage subsystem and having a first threshold for controlling for each of said host computers an occupancy ratio of the write data whose copy to said second storage subsystem is incomplete in a data buffer in said first storage subsystem, and control logic for delaying the processing of a data write request from each of said host computers on the basis of said first threshold which is set for each of said host computers.
A method of controlling a storage subsystem including a first storage subsystem connected to a plurality of host computers via a first interface and a second storage subsystem connected to said first storage subsystem via a second interface so as to copy write data written in said first storage subsystem from said host computer onto said second storage subsystem from said first storage subsystem, thereby protecting the write data in said first and said second storage subsystems in a multiplex manner, said method comprising:
- a first step of setting for each of said host computers a first threshold for controlling an occupancy ratio of the write data whose copy to said second storage subsystem is incomplete in a data buffer in said first storage subsystem;
- and
- a second step of delaying the processing of a data write request from each of said host computers on the basis of said first threshold which is set for each of said host computers.
Dependencies are inferred from the claim text.