Modification of a cluster of communication controllers

Abstract

Provided is a system having a cluster of communication controllers, a method for modification of the latter, and a computer program product carrying computer executable code for execution of the method. Each communication controller is operable for providing network connections of the system with external computer systems using communication protocols of a first type and a second type. The first type is a failover tolerant communication protocol type. The second type is a failover non-tolerant communication protocol type. All network connections of each communication controller are disconnected during the modification of said communication controller. The method for modifying the cluster of communication controllers includes splitting the communication controllers into a first pool and a second pool.

What is claimed is: 
     
         1 . A method of modifying communication controllers of a clustered storage system, wherein each communication controller of the clustered storage system is communicatively located between at least one external network and at least one internal storage system network and includes a unique access point for communication with the at least one external network, the method comprising:
 splitting the communication controllers of the clustered storage system into a first pool comprising at least one communication controller and a second pool comprising at least another one communication controller, wherein each communication controller of the clustered storage system is operable to establish network connections with external computer systems such that the external computer systems are connected with the clustered storage system using communication protocols of one or both of a first type and a second type, wherein the first type is a failover tolerant communication protocol type and the second type is a failover non-tolerant communication protocol type, wherein initially each communication controller of the first pool provides the network connections with the external computer systems using communication protocols of the first type, and wherein initially each communication controller of the second pool provides the network connections with the external computer systems using communication protocols of the second type;   modifying a portion of the communication controllers of the clustered storage system consisting of one or more communication controllers of the first pool, wherein modifying the portion of the communication controllers comprises temporarily transferring from the first pool to the second pool at least one modified controller providing the network connections with the external computer systems using communication protocols of at least the second type; and   after modifying the portion of the communication controllers, modifying at least one next portion of the communication controllers until all of the communication controllers of the clustered storage system are modified.   
     
     
         2 . The method of  claim 1 , wherein each network connection provided by a communication controller using a communication protocol of the first type that is disconnected during communication controller modification is automatically reestablished. 
     
     
         3 . The method of  claim 1 , wherein each network connection provided by a communication controller using a communication protocol of the second type that is disconnected during communication controller modification is reestablished via a reestablishment command. 
     
     
         4 . The method of  claim 1 , wherein at least one communication controller of the second pool provides the network connections with the external computer systems using communication protocols of both the first type and the second type. 
     
     
         5 . The method of  claim 1 , wherein all of the communication controllers of the first pool are modified before the communication controllers of the second pool. 
     
     
         6 . The method of  claim 5 , wherein each modified controller of the first pool provides the network connections with the external computer systems using communication protocols of both the first type and the second type during modification of the second pool. 
     
     
         7 . The method of  claim 1 , wherein a portion of the communication protocols of the first type are stateless file-based data protocols. 
     
     
         8 . The method of  claim 1 , wherein a portion of the communication protocols of the second type are stateful file-based data protocols. 
     
     
         9 . A clustered storage system comprising communication controllers, wherein each communication controller of the clustered storage system is communicatively located between at least one external network and at least one internal storage system network and includes a unique access point for communication with the at least one external network, the clustered storage system being operable for:
 splitting the communication controllers of the clustered storage system into a first pool comprising at least one communication controller and a second pool comprising at least another one communication controller, wherein each communication controller of the clustered storage system is operable to establish network connections with external computer systems such that the external computer systems are connected with the clustered storage system using communication protocols of one or both of a first type and a second type, wherein the first type is a failover tolerant communication protocol type and the second type is a failover non-tolerant communication protocol type, wherein initially each communication controller of the first pool provides the network connections with the external computer systems using communication protocols of the first type, and wherein initially each communication controller of the second pool provides the network connections with the external computer systems using communication protocols of the second type;   modifying a portion of the communication controllers of the clustered storage system consisting of one or more communication controllers of the first pool, wherein modifying the portion of the communication controllers comprises temporarily transferring from the first pool to the second pool at least one modified controller providing the network connections with the external computer systems using communication protocols of at least the second type; and   after modifying the portion of the communication controllers, modifying at least one next portion of the communication controllers until all of the communication controllers of the clustered storage system are modified.   
     
     
         10 . The clustered storage system of  claim 9 , wherein each network connection provided by a communication controller using a communication protocol of the first type that is disconnected during communication controller modification is automatically reestablished. 
     
     
         11 . The clustered storage system of  claim 9 , wherein each network connection provided by a communication controller using a communication protocol of the second type that is disconnected during communication controller modification is reestablished via a reestablishment command. 
     
     
         12 . The clustered storage system of  claim 9 , wherein at least one communication controller of the second pool provides the network connections with the external computer systems using communication protocols of both the first type and the second type. 
     
     
         13 . The clustered storage system of  claim 9 , wherein all of the communication controllers of the first pool are modified before the communication controllers of the second pool. 
     
     
         14 . The clustered storage system of  claim 13 , wherein each modified controller of the first pool provides the network connections with the external computer systems using communication protocols of both the first type and the second type during modification of the second pool. 
     
     
         15 . A computer program product for modification of communication controllers of a clustered storage system, wherein each communication controller of the clustered storage system is communicatively located between at least one external network and at least one internal storage system network and includes a unique access point for communication with the at least one external network, and wherein the computer program product comprises a computer readable storage medium having computer readable program code embodied therewith, the computer readable program code comprising computer readable program code configured to:
 split the communication controllers of the clustered storage system into a first pool comprising at least one communication controller and a second pool comprising at least another one communication controller, wherein each communication controller of the clustered storage system is operable to establish network connections with external computer systems such that the external computer systems are connected with the clustered storage system using communication protocols of one or both of a first type and a second type, wherein the first type is a failover tolerant communication protocol type and the second type is a failover non-tolerant communication protocol type, wherein initially each communication controller of the first pool provides the network connections with the external computer systems using communication protocols of the first type, and wherein initially each communication controller of the second pool provides the network connections with the external computer systems using communication protocols of the second type;   modify a portion of the communication controllers of the clustered storage system consisting of one or more communication controllers of the first pool, wherein modifying the portion of the communication controllers comprises temporarily transferring from the first pool to the second pool at least one modified controller providing the network connections with the external computer systems using communication protocols of at least the second type; and   after modifying the portion of the communication controllers, modify at least one next portion of the communication controllers until all of the communication controllers of the clustered storage system are modified.   
     
     
         16 . The computer program product of  claim 15 , wherein each network connection provided by a communication controller using a communication protocol of the first type that is disconnected during communication controller modification is automatically reestablished. 
     
     
         17 . The computer program product of  claim 15 , wherein each network connection provided by a communication controller using a communication protocol of the second type that is disconnected during communication controller modification is reestablished via a reestablishment command. 
     
     
         18 . The computer program product of  claim 15 , wherein at least one communication controller of the second pool provides the network connections with the external computer systems using communication protocols of both the first type and the second type. 
     
     
         19 . The computer program product of  claim 15 , wherein all of the communication controllers of the first pool are modified before the communication controllers of the second pool. 
     
     
         20 . The computer program product of  claim 19 , wherein each modified controller of the first pool provides the network connections with the external computer systems using communication protocols of both the first type and the second type during modification of the second pool.