Remote data shadowing using a multimode interface to dynamically reconfigure control link-level and communication link-level
First Claim
1. A method of communicating between a host processor, a first storage subsystem, and a second storage subsystem, the host processor, and first and second storage subsystems coupled together by at least one communication link, the host processor and each first and second storage subsystems each having at least one link-level facility, the method comprising machine effected steps of:
- (a) initializing paths between the host processor and the first and second storage subsystems, wherein the host processor link-level facility is configured as a channel, and the first and second storage subsystem link-level facilities are each configured as a control unit link-level facility;
(b) configuring paths between the host processor and the first and second storage subsystems;
(c) establishing logical paths between the first and second storage subsystems, wherein the first storage subsystem link-level facility is dynamically re-configured as a channel link-level facility, the first storage subsystem acting as a host to the second storage subsystem; and
(d) establishing pathing control between the first and second storage subsystems, wherein the first storage subsystem transmits an establish pathing control (EPC) frame to the second storage subsystem for processing.
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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. Using dynamic switches coupled between primary and secondary sites, fewer ESCON communication links are required since the ESCON communication links can function either as a channel or as storage controller communication link.
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Citations
17 Claims
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1. A method of communicating between a host processor, a first storage subsystem, and a second storage subsystem, the host processor, and first and second storage subsystems coupled together by at least one communication link, the host processor and each first and second storage subsystems each having at least one link-level facility, the method comprising machine effected steps of:
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(a) initializing paths between the host processor and the first and second storage subsystems, wherein the host processor link-level facility is configured as a channel, and the first and second storage subsystem link-level facilities are each configured as a control unit link-level facility; (b) configuring paths between the host processor and the first and second storage subsystems; (c) establishing logical paths between the first and second storage subsystems, wherein the first storage subsystem link-level facility is dynamically re-configured as a channel link-level facility, the first storage subsystem acting as a host to the second storage subsystem; and (d) establishing pathing control between the first and second storage subsystems, wherein the first storage subsystem transmits an establish pathing control (EPC) frame to the second storage subsystem for processing. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10)
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11. A storage controller for communicating with a host processor and receiving data therefrom and communicating with another storage controller over at least one enterprise system connection (ESCON) link, the host processor having a channel link-level facility port, the storage controller comprising:
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a serial adapter for connecting to the ESCON link; a storage path for providing a data path for data received in the storage controller for storage; and at least one link level facility dynamically reconfigurable as a control unit link-level facility for communicating with the host processor over the ESCON link, and further dynamically re-configurable as a channel link-level facility for communicating with the another storage controller over the ESCON link, wherein the storage controller acts as host to the another storage controller. - View Dependent Claims (12, 13, 14, 15, 16)
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17. A remote dual copy system, comprising:
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a primary host having at least one channel; a primary storage subsystem having at least one link-level facility; a secondary host having at least one channel; a secondary storage subsystem having at least one link-level facility; at least one communication link; and a dynamic switch coupling the primary and secondary hosts and the primary and secondary storage subsystems via the at least one communication link and corresponding channels and link-level facilities, wherein the primary host initiates a remote copy session communicating with the primary and secondary storage subsystems and initializes paths thereto, the at least one link-level facility of the primary and secondary storage subsystems operating in a control unit link-level facility mode, and further wherein the at least one primary storage subsystem link-level facility is dynamically re-configured for operating in a channel link-level facility mode, the primary storage subsystem acting as a host to the secondary storage subsystem and establishing logical paths and pathing control therebetween, the primary storage controller intercepting primary host write commands for sending modified data to the secondary storage subsystem.
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Specification