Remote copy system for setting request interconnect bit in each adapter within storage controller and initiating request connect frame in response to the setting bit
First Claim
1. A method of communicating between a first storage subsystem and a second storage subsystem, said first and second storage subsystems coupled together by a plurality of communication links, said first and second storage subsystems each having a plurality of ports for connection to said plurality of communication links, said method comprising machine effected steps of:
- (a) initializing a plurality of paths between said first and second storage subsystems over said plurality of communication links;
(b) configuring said plurality of paths between said first and second storage subsystems;
(c) establishing logical paths between said first and second storage subsystems, wherein said first storage subsystem has link-level facilities configured as channel link-level facilities, said first storage subsystem acting as a host to said second storage subsystem having link-level facilities configured as a control unit link-level facilities;
(d) performing an I/O process wherein said first storage subsystem requiring execution of a CCW to said second storage subsystem;
(e) requesting an I/O connection at said first storage subsystem concurrently over at least first and second ports of said plurality of ports of said first storage subsystem, wherein said step (e) further comprises setting a Request Initiation (RQI) bit accessible to said first and second ports of said plurality of ports in said first storage subsystems; and
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(f) concurrently sending a Request Connect (RQC) frame from each said first and second ports.
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Accused Products
Abstract
A remote copy system incorporates dynamically modifiable ports on the storage controllers such that those ports can operate either as a control unit link-level facility or as a channel link-level facility. When configured as a channel link-level facility, a primary storage controller can appear as a host processor to a secondary storage controller. The primary storage controller can thereafter initiate multiple request connects (RQC) concurrently for servicing a single I/O request. In this manner, a first available path can be selected and system throughput thus improved since RQCs so not need to be sent serially from path to path looking for an available path.
276 Citations
15 Claims
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1. A method of communicating between a first storage subsystem and a second storage subsystem, said first and second storage subsystems coupled together by a plurality of communication links, said first and second storage subsystems each having a plurality of ports for connection to said plurality of communication links, said method comprising machine effected steps of:
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(a) initializing a plurality of paths between said first and second storage subsystems over said plurality of communication links; (b) configuring said plurality of paths between said first and second storage subsystems; (c) establishing logical paths between said first and second storage subsystems, wherein said first storage subsystem has link-level facilities configured as channel link-level facilities, said first storage subsystem acting as a host to said second storage subsystem having link-level facilities configured as a control unit link-level facilities; (d) performing an I/O process wherein said first storage subsystem requiring execution of a CCW to said second storage subsystem; (e) requesting an I/O connection at said first storage subsystem concurrently over at least first and second ports of said plurality of ports of said first storage subsystem, wherein said step (e) further comprises setting a Request Initiation (RQI) bit accessible to said first and second ports of said plurality of ports in said first storage subsystems; and
;(f) concurrently sending a Request Connect (RQC) frame from each said first and second ports. - View Dependent Claims (2, 3, 4, 5, 6, 7)
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8. A storage controller, having microcode therein, for communicating with a host processor for initiating an I/O and receiving data therefrom and communicating with another storage controller over a plurality of enterprise system connection (ESCON) links, the storage controller comprising:
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a plurality of serial adapters for connecting to the ESCON links, each serial adapter having acess to a corresponding request interconnect bit (RQI), the RQI bits being set by the microcode in response to the I/O initiative, said plurality of serial adapters responding to set RQI bits by concurrently sending request connect (RQC) frames over the plurality of ESCON links; a storage path for providing a data path for data received in the storage controller for storage; at least one link level facility configured as control unit link-level facility for communicating with the host processor over a first ESCON link; and a plurality of link level facilities configured as channel link-level facilities for communicating with the another storage controller over the ESCON links, wherein the storage controller acts as host to the another storage controller. - View Dependent Claims (9, 10, 11, 12, 13)
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14. A remote dual copy system, comprising:
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a primary host having at least one channel; a primary storage subsystem coupled to said primary host by said at least one channel, said primary storage subsystem having a plurality of link-level facilities; a secondary storage subsystem having a plurality of link-level facilities; and a plurality of communication links coupling said primary and secondary storage subsystems; said primary storage subsystem further comprising a storage controller controlled by microcode therein and having a plurality of ports, each port having a serial adapter for controlling communications therewith, wherein said microcode sets a request interconnect (RQI) bit in each serial adapter for servicing an I/O operation within said storage controller, each serial adapter initiating a request connect (RQC) frame in response to having a set RQI bit, a serial adapter first receiving a grant frame from said secondary storage subsystem responding by notifying said microcode, said microcode thereafter resetting the RQI bits. - View Dependent Claims (15)
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Specification