Storage system providing stream-oriented performance assurance

Abstract

The transfer rates of streams are assured if the plural streams are mixed. A disk array system required to process multiple streams from a host computer carries out recognition of the transfer rates, recognition of drive performance and a fault processing time, determines the size of a sequential buffer holding each stream, and determines the drive I/O size. Using the transfer rate and buffer size determined in these processing steps, required end times at which prefetch and destage should be terminated are found. Based on the times, the I/O priorities are determined.

1 . A storage system comprising: 
 a controller connectable to a plurality of computers; and    a plurality of storage devices connected to the controller,    wherein the plurality of storage devices store a plurality of contents,    wherein the controller receives a first request from a one of the plurality of computers which requests access to a first content of the plurality of contents,    wherein the controller calculates first data transfer rate of the first request, and    wherein the controller executes a plurality of processes of the first request based/on a result of calculation.    
   
   
       2 . A storage system according to  claim 1 , 
 wherein the controller executes the plurality of processes within a first period of time to maintain the first data transfer rate, and    wherein the first period of time is calculated based on a resource and performance of the storage system, and the first data transfer rate.    
   
   
       3 . A storage system according to  claim 2 , 
 wherein the controller receives a second request which requests access to a second content of the plurality of contents, calculates a second data transfer rate of the second request, and executes a plurality of second processes of the second request based on the second data transfer rate.    
   
   
       4 . A storage system according to  claim 3 , 
 wherein the controller executes the plurality of second processes within a second period of time to maintain the second data transfer rate, and    wherein the second period of time is calculated based on the resource and performance of the storage system, and the second data transfer rate.    
   
   
       5 . A storage system according to  claim 4 , 
 wherein the controller compares a ending time of the first period of time and the second period of time, and executes the plurality of second processes prior to the plurality of processes if the ending time of the second period of time is earlier than the ending time of the first period of time.    
   
   
       6 . A storage system according to  claim 5 , comprising a memory, 
 wherein the controller configures memory area of the memory used by the plurality of processes based on the first data transfer rate.    
   
   
       7 . A storage system according to  claim 6 , 
 wherein, if the controller received the first request, the controller sends data based on a maximum data transfer rate of the storage system to the one of the plurality of computers, checks an amount of transferring data between the storage system and-the one of the plurality of computers and calculates the first data transfer rate based on the amount of transferring data.    
   
   
       8 . A storage system according to  claim 7 , wherein the controller configures a plurality of logical units based on the plurality of storage drives, 
 wherein a first logical unit of the plurality of logical units stores the first content of the plurality of contents and a second logical unit of the plurality of logical units stores the second content, and    wherein the controller calculates a data transfer rate for the first logical unit as the first data transfer rate, and calculates a data transfer rate for the second logical unit as the second data transfer rate.    
   
   
       9 . A storage system according to  claim 7 , 
 wherein the controller checks whether the first request indicates a sequential access or not, and calculates the first data transfer rate if the first request indicates the sequential access.    
   
   
       10 . A storage system according to  claim 7 , 
 wherein the controller stores information of the first data transfer rate, and uses the information of the first data transfer rate if the controller receives the first request again.    
   
   
       11 . A data transfer method used in a storage system that stores a plurality of contents, comprising: 
 receiving a first request from a one of a plurality of connected to the storage system which requests to access to a first content/of the plurality of contents;    calculating a first data transfer rate of the first request; and    sending data requested by the first request based on a result of calculation.    
   
   
       12 . A data transfer method according to  claim 11  comprising: executing a plurality of processes for transferring the data within a first period of time to maintain the first data transfer rate, and 
 wherein the first period of time is calculated based on a resource and performance of the storage system and the first data transfer rate.    
   
   
       13 . A data transfer method according to  claim 12  comprising: 
 receiving a second request which requests access to a second content of the plurality of contents;    calculating a second data transfer rate of the second request; and    sending second data requested by the second request based on the second data transfer rate.    
   
   
       14 . A data transfer method according to  claim 13  comprising: executing a plurality of second processes for sending the second data within a second period of time to maintain the second data transfer rate, and 
 wherein the second period of time is calculated based on the resource and performance of the storage system and the second data transfer rate.    
   
   
       15 . A data transfer method according to  claim 14  comprising: 
 comparing a ending time of the first period of time and the second period of time; and    executing the plurality of second processes prior to the plurality of processes if the ending time of the second period of time is earlier than the ending time of the first period of time.    
   
   
       16 . A data transfer method according to  claim 15 , wherein the calculating includes: 
 sending data based on a maximum data transfer rate of the storage system to the one of the plurality of computers responding to the first request;    checking an amount of transferring data between the storage system and the one of the plurality of computers; and    calculating the first data transfer rate based on the amount of transferring data.    
   
   
       17 . A data transfer method according to  claim 16 , wherein the calculating includes: 
 checking whether the first request received from the one of the plurality of computers indicates a sequential access or not; and    calculating the first data transfer rate indicated if the first request indicates the sequential access.    
   
   
       18 . A storage system comprising: 
 a means for storing a plurality of contents;    a means for receiving a first request from a one of a plurality of computers connected to the storage system which requests access to a first content of the plurality of contents;    a means for receiving a second request which requests access to a second content of the plurality of contents;    a means for calculating a first data transfer rate of the first request and a second data transfer rate of the second request; and    a means for sending data requested by the first request based on a result of calculation and second data requested by the second request based on the second data transfer rate.    
   
   
       19 . A storage system according to  claim 11  comprising: 
 means for executing a plurality of processes for transferring the data within a first period of time to maintain the first data transfer rate, and executing a plurality of second processes for sending the,second data within a second period of time to maintain the second data transfer rate,    wherein the first period of time is calculated based on a resource and performance of the storage system and the first data transfer rate, and the second period of time is calculated based on the resource and performance of the storage system and the second data transfer rate.    
   
   
       20 . A storage system according to  claim 19  comprising: 
 means for comparing a ending time of the first period of time and the second period of time; and    means for executing the plurality of second processes prior to the plurality of processes if the ending time of the second period of time is earlier than the ending time of the first period of time.