Disk control system and control method of disk control system

Abstract

In order to assign logical devices efficiently to logical units, a disk control system that receives a process command for writing or reading of data from an information processing device, and performs a write or read process of data with respect to a logical device corresponding to a logical unit specified by that process command, includes means for managing logical devices, which are logical storage regions that have been set in a storage region provided by a disk drive, means for storing a correspondence between logical units, which are storage regions that have been set logically, and the logical devices, and means for assigning, when a process command has been received for a logical unit to which no logical device has been assigned, a logical device to that logical unit and performing processing with regard to that logical device.

1 . A disk array device, comprising: 
 a plurality of disk drives; and    a controller for controlling a data read or write command sent from a host computer with respect to a plurality of logical units corresponding to the plurality of disk drives,    wherein the controller, when receiving from the host computer a first write command with respect to a first logical unit of the plurality of logical units, assigns to the first logical unit a first storage region having available storage capacity greater than the amount of data associated with the first write command.    
   
   
       2 . A disk array device according to  claim 1 , wherein: 
 the controller, when receiving from the host computer a second write command with respect to the first logical unit, if the available storage capacity of the first storage region already assigned to the first logical unit is less than the amount of data associated with the second write command, then assigns to the first logical unit a second storage region having available storage capacity greater than a remaining portion of the data associated with the second write command that cannot be stored in the first storage region already assigned.    
   
   
       3 . A disk array device according to  claim 1 , wherein: 
 the controller, when receiving from the host computer a command in accordance with the SCSI standard, determines based on the type of this SCSI command whether or not to add a new storage region to the existing first storage region.    
   
   
       4 . A disk array device according to  claim 3 , wherein: 
 the controller, if the SCSI command is to request information regarding the first logical unit, then replies to this SCSI command without adding the new storage region to the existing first storage region.    
   
   
       5 . A disk array device according to  claim 3 , wherein: 
 the controller, if the SCSI command is the write command, then adds the new storage region to the existing first storage region.    
   
   
       6 . A disk array device according to  claim 3 , wherein: 
 the controller, if the SCSI command is a “Report LUN” command, then replies to this SCSI command without adding the new storage region to the existing first storage region.    
   
   
       7 . A disk array device according to  claim 3 , wherein: 
 the controller, if the SCSI command is an “Inquiry” command, then replies to this SCSI command without adding the new storage region to the existing first storage region.    
   
   
       8 . A disk array device according to  claim 3 , wherein: 
 the controller, if the SCSI command is a “Read Capacity” command, then replies to this SCSI command without adding the new storage region to the existing first storage region.    
   
   
       9 . A control method for a disk array device that includes a plurality of disk drives and a controller for controlling a data read or write command sent from a host computer with respect to a plurality of logical units corresponding to the plurality of disk drives, the control method comprising a step of: 
 when receiving from the host computer a first write command with respect to a first logical unit of the plurality of logical units, assigning to the first logical unit a first storage region having available storage capacity greater than the amount of data associated with the first write command.    
   
   
       10 . A control method according to  claim 9 , further comprising a step of: 
 when receiving from the host computer a second write command with respect to the first logical unit, if the available storage capacity of the first storage region already assigned to the first logical unit is less than the amount of data associated with the second write command, then assigning to the first logical unit a second storage region having available storage capacity greater than a remaining portion of the data associated with the second write command that cannot be stored in the first storage region already assigned.    
   
   
       11 . A control method according to  claim 9 , further comprising a step of: 
 when receiving from the host computer a command in accordance with the SCSI standard, determining based on the type of this SCSI command whether or not to add a new storage region to the existing first storage region.    
   
   
       12 . A control method according to  claim 11 , further comprising a step of: 
 if the SCSI command is to request information regarding the first logical unit, then replying to this SCSI command without adding the new storage region to the existing first storage region.    
   
   
       13 . A control method according to  claim 11 , further comprising a step of: 
 if the SCSI command is the write command, then adding the new storage region to the existing first storage region.    
   
   
       14 . A control method according to  claim 11 , further comprising a step of: 
 if the SCSI command is a “Report LUN” command, then replying to this SCSI command without adding the new storage region to the existing first storage region.    
   
   
       15 . A control method according to  claim 11 , further comprising a step of: 
 if the SCSI command is an “Inquiry” command, then replying to this SCSI command without adding the new storage region to the existing first storage region.    
   
   
       16 . A control method according to  claim 11 , further comprising a step of: 
 if the SCSI command is a “Read Capacity” command, then replying to this SCSI command without adding the new storage region to the existing first storage region.