Information processing system for sharing internal auxiliary storage device

Abstract

An OS executed by a CPU employed in an information processing apparatus prepares a series of CCW commands and data to be transmitted or an area for receiving data in a main storage device, and issues a request to start an operation of an I/O function to an auxiliary-storage-device control unit. Receiving the request to start an operation of the I/O function, the auxiliary-storage-device control unit emulates each command in the series of CCWs to transmit or receive the data to or from another information processing apparatus, generating a command set to request the other information processing apparatus employing an embedded disk unit that information be read out from the disk unit. As requested by this command set, the embedded disk unit outputs a response and the information to the information processing apparatus preparing the series of CCW commands by way of a communication unit employed in the other information processing apparatus and a communication bus before the data is exchanged between the apparatuses. Finally, the data is transmitted to or received from the other information processing apparatus. As a result, the embedded disk unit employed in the other information processing apparatus as an internal auxiliary storage device can be accessed by the information processing apparatus preparing the series of CCW commands at a high speed.

What is claimed is:  
     
         1 . An input/output control system comprising a first information processing apparatus including a central processing unit, a main storage device and an internal auxiliary storage device, and one or a plurality of second information processing apparatuses each including a central processing unit, a main storage device and a communication unit for communicating with another information processing apparatus wherein any of said second information processing apparatuses makes an access to said internal auxiliary storage device of said first information processing apparatus, 
 said first and second information processing apparatuses each comprising an auxiliary-storage-device control unit for controlling operations to read out and write information from and into said internal auxiliary storage device wherein said auxiliary-storage-device control unit of any of said second information processing apparatuses: 
 emulates an auxiliary storage format controlled by one command or a plurality of commands forming a series of commands stored in said main storage device employed by said secondary information processing apparatus employing said auxiliary-storage-device control unit in an auxiliary storage format executed by said auxiliary-storage-device control unit employed in said first information processing unit in order to make an access to said internal auxiliary storage device; and  
 transmits a result of emulation to said first information processing apparatus by way of said communication unit employed by said secondary information processing apparatus employing said auxiliary-storage-device control unit.  
   
     
     
         2 . An input/output control system according to  claim 1  wherein said first and second information processing apparatuses each have a cache for an internal auxiliary storage device and, when any of said first and second information processing apparatuses makes a request for an operation to update a piece of data stored in said internal auxiliary storage device or stored in said cache in said first information processing apparatus, said information processing apparatuses other than said information processing apparatus making said request are informed of said operation to update a piece of data or replacement data used for updating said piece of data.  
     
     
         3 . An input/output control system according to  claim 2  wherein communications between said first information processing apparatus and said second information processing apparatuses are divided into two types of communication with different protocols, namely, a communication to exchange control data for controlling said caches for said internal auxiliary storage device employed in said first information processing apparatus and a communication to read out and write data from and into said internal auxiliary storage device.  
     
     
         4 . An input/output control system according to  claim 2  wherein said first information processing apparatus further has a table including: 
 a field for declaring an exclusive use of said internal auxiliary storage device employed in said first information processing apparatus;  
 a field for storing information indicating which of said information processing apparatuses is using said internal auxiliary storage device; and  
 validity flags indicating whether or not contents of said fields are valid.  
 
     
     
         5 . An input/output control system according to  claim 4  wherein information stored in said table is used for identifying said information processing apparatuses to be informed of an operation to replace a piece of data stored in said internal auxiliary storage device or stored in said cache in said first information processing apparatus or to be informed of replacement data used for replacing said piece of data.  
     
     
         6 . A computer system comprising a plurality of information processing apparatuses each including a central processing unit, a main storage device, an auxiliary-storage-device control unit and a communication unit for communicating with other information processing apparatuses, wherein one of said information processing apparatuses has an internal auxiliary storage device and the other information processing apparatuses each make accesses to said internal auxiliary storage device through said auxiliary-storage-device control unit thereof.  
     
     
         7 . A computer system according to  claim 6  wherein said information processing apparatuses each have an internal-auxiliary-storage-device cache and, when any of said information processing apparatuses-makes a request for an operation to replace a piece of data in said internal auxiliary storage device, said information processing apparatuses other than said information processing apparatus making said request are informed that said piece of data is replaced or informed of replacement data used for replacing said piece of data.  
     
     
         8 . A computer system according to  claim 7  wherein said information processing apparatus making said request further has a table including: 
 a field for declaring an exclusive use of said internal auxiliary storage device;  
 a field for storing information indicating which of said information processing apparatuses is using said internal auxiliary storage device; and  
 validity flags indicating whether or not contents of said fields are valid.  
 
     
     
         9 . A computer system according to  claim 8  wherein information stored in said table is used for identifying one of said information processing apparatuses to be informed of an operation to replace a piece of data stored in said internal auxiliary storage device or to be informed of replacement data used for replacing said piece of data.