Flexible data replication mechanism

Abstract

A data replication management (DRM) architecture comprising a plurality of storage cells interconnected by a fabric. Flexibility in connectivity is provided by configuring each storage cell port to the fabric to handle both host data access requests and DRM traffic. Each storage cell comprises one or more storage controllers that can be connected to the fabric in any combination. Processes executing in the storage controller find a path to a desired destination storage cell. The discovery algorithm implements a link service that exchanges information related to DRM between the storage controllers. The DRM architecture is symmetric and peer cooperative such that each controller and storage cell can function as a source and a destination of replicated data. The DRM architecture supports parallel and serial “fan-out” to multiple destinations, whereby the multiple storage cells may implement data replicas.

1 - 17 . (canceled)  
   
   
       18 . A SAN storage controller comprising: 
 a data processor system configured to implement software processes;    at least one host port;    a pool of storage accessible through the data processor system;    processes executing in the processor to enable the at least one host port to couple to an external communication network;    processes executing in the processor for communicating data access requests with the at least one host port; and    processes executing in the processor for communicating data replication transactions with external storage controllers through the at least one host port.    
   
   
       19 . The storage controller of  claim 18  wherein the at least one port handles both data access requests and data replication transactions.  
   
   
       20 . The storage controller of  claim 18  further comprising at least two host ports.  
   
   
       21 . The storage controller of  claim 18  further comprising more than two host ports.  
   
   
       22 . The storage controller of  claim 18  further comprising processes within the controller causing the controller to register with a name server in the external communication network.  
   
   
       23 . The storage controller of  claim 22  wherein the name server stores a storage cell universally unique identification (UUID) value.  
   
   
       24 . The storage controller of  claim 23  further comprising processes for discovering external storage controllers coupled to the external communications network using the UUID registration information in the name server.  
   
   
       25 . The storage controller of  claim 18  wherein the at least one port comprises a fibre channel port.  
   
   
       26 . The storage controller of  claim 18  further comprising processes executing in the processor to virtualize the storage capacity.  
   
   
       27 . A storage controller, comprising: 
 a first port adapted to provide a connection to a switch and configured to handle data transactions and data replication traffic;    a second port adapted to provide a connection to a switch and configured to handle data transactions and data replication traffic, wherein: 
 the first port serves as a primary port for a data replication operation with a first destination and a redundant port for a data replication operation with a second destination;  
 the second port serves as a primary port for a data replication operation with a second destination and a redundant port for a data replication operation with a first destination;  
 data transactions and data replication traffic managed by the first port are routed to the second port in when a data replication operation fails on the first controller; and  
 data transactions and data replication traffic managed by the second port are routed to the first port in when a data replication operation fails on the first controller.  
   
   
   
       28 . The storage controller of  claim 27 , wherein at least one port is adapted to maintain a Fibre Channel Arbitrated Loop connection.  
   
   
       29 . The storage controller of  claim 27 , wherein the storage controller comprises a unique identification number.  
   
   
       30 . The storage controller of  claim 27 , wherein in response to a connection failure, the storage controller migrates data replication operations to a separate storage controller.  
   
   
       31 . A data replication controller, comprising: 
 a data processor system configured to implement a software process;    a first port adapted to provide a connection to a switch and configured to handle data transactions and data replication traffic;    a second port adapted to provide a connection to a switch and configured to handle data transactions and data replication traffic;    a pool of storage accessible through the data replication controller;    a first software process executing in the data processor to enable the first host port to couple to an external communication network;    a second software process executing in the data processor to designate a source virtual disk in the pool of storage; and    a third process processes executing in the processor to create a destination virtual disk in the pool of storage.    
   
   
       32 . The data replication controller of  claim 31 , wherein the first port and the second port communicate with a plurality of host systems to handle host data operations and with each other to handle data operations.  
   
   
       33 . The data replication controller of  claim 31 , wherein at least one port is adapted to maintain a Fibre Channel Arbitrated Loop connection.  
   
   
       34 . The data replication controller of  claim 31 , wherein the controller comprises a unique identification number.  
   
   
       35 . The data replication controller of  claim 31 , wherein in response to a connection failure, the data replication controller migrates data replication operations to a separate controller.