Abstract:
An information processing apparatus comprises: a creation unit creating a preset number of pieces of second data by duplicating first data, and holding the second data in a predetermined area or sending the second data to another information processing apparatus; a first writing unit for writing the first data in a first storage device; an activation unit activating power to a second storage device at a predetermined time, the second storage device being in a stopped state; a second writing unit for writing the second data in the second storage device activated by the activation unit by retrieving the second data from the predetermined area or another information processing apparatus after the second storage device is activated by the activation unit; a stop unit stopping power to the second storage device in which the second data is written by the second writing unit.

Description:
CROSS-REFERENCES TO RELATED APPLICATIONS 
     This application relates to and claims priority from Japanese Patent Application No. 2008-114299, filed on Apr. 24, 2008, the entire disclosure of which is incorporated herein by reference. 
     BACKGROUND 
     The invention relates generally to an information processing device, data writing method, and program for the same, and is suitable for application in, for example, storage system provided with a plurality of archive nodes. 
     Usually, a distributed archive technique involving, when archive data (master archive data) sent from an archive server and a write request are received, copying the number of pieces of archive data based on a predetermined policy and holding those pieces of archive data on a plurality of archive nodes so as to maintain the reliability of master data of archive data, has been widely used (e.g., see JP2007-511820 T). 
     Meanwhile, a power-saving technique of stopping the power of an HDD (Hard Disk Drive) constituting a volume which has not been accessed from a server for a certain period of time, thereby reducing power consumption of storage device, has also been widely used (e.g., see JP2007-156597 A). 
     SUMMARY 
     However, with the combination of the conventional distributed archive technique and power-saving technique, the following problem exists when stopping the power of an HDD, which constitute a volume of archive data kept by means of the distributed archive technique and has not been accessed for a certain period of time, by means of the power-saving technique. 
     More specifically, the copy of archive data created by means of the distributed archive technique is used only when the master data for the archive data is lost, so the copy is hardly ever referred to. However, in the distributed archive technique, there is a case when master archive data and the copy of archive data are written in a single volume regardless of HDDs constituting a volume, and the power of the HDDs cannot be turned-off because all HDDs are frequently accessed, so there is a problem in that the power consumption of storage device cannot be reduced. 
     The present invention has been devised in consideration of the above-described points, and it is an object of the present invention to provide an information processing device, data writing method, and program that are capable of dramatically improving operational efficiency. 
     In order to solve the aforementioned problem, according to an aspect of the invention, an information processing apparatus comprises: a creation unit creating a preset number of pieces of second data by duplicating first data sent from a host computer, and holding the second data in a predetermined area or sending the second data to another information processing apparatus; a first writing unit for writing the first data in a first storage device in which the first data is to be written; an activation unit activating power to a second storage device in which the second data is to be written at a predetermined time, the second storage device being in a stopped state; a second writing unit for writing the second data in the second storage device activated by the activation unit by retrieving from the predetermined area or another information processing apparatus the second data that is to be written in the second storage device after the second storage device is activated by the activation unit; and a stop unit stopping power to the second storage device in which the second data is written by the second writing unit. 
     According to another aspect of the invention, a data writing method in an information processing apparatus comprises: a first step where a creation unit creates a preset number of pieces of second data by duplicating first data sent from a host computer, and the creation unit holds the second data in a predetermined area or sends the second data to another information processing apparatus; a second step where a writing unit writes the first data in a first storage device in which the first data is to be written; a third step where an activation unit activates power to a second storage device in which the second data is to be written at a predetermined time, the second storage device being in a stopped state; a fourth step where the writing unit writes the second data in the second storage device activated in the third step by retrieving from the predetermined area or another information processing apparatus the second data that is to be written in the second storage device after the second storage device is activated in the third step; and a fifth step where a stop unit stops power to the second storage device in which the second data is written in the fourth step. 
     According to yet another aspect of the invention, a program for an information processing apparatus executes: a first step of creating a preset number of pieces of second data by duplicating first data sent from a host computer, and holding the second data in a predetermined area or sending the second data to another information processing apparatus; a second step of writing the first data in a first storage device in which the first data is to be written; a third step of activating power to a second storage device in which the second data is to be written at a predetermined time, the second storage device being in a stopped state; a fourth step of writing the second data in the second storage device activated in the third step by retrieving from the predetermined area or another information processing apparatus the second data that is to be written in the second storage device after activating the second storage device in the third step; and a fifth step of stopping power to the second storage device in which the second data is written in the fourth step. 
     Accordingly, the copy data of the first data and second data is written to two storage devices: the first storage device, which is a location where the first data is to be written; and the second storage device, which is an area where the second data is to be written, and is in a stopped state, so the running time of the second storage device can be minimized and the power consumption can be effectively reduced. 
     According to the present invention, an information processing device, data writing method, and program that are capable of dramatically improving operational efficiency can be realized. 
     Other aspects and advantages of the invention will be apparent from the following description and the appended claims. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a block diagram showing the configuration of storage system according to the embodiment. 
         FIG. 2  is a block diagram showing the configuration of a server. 
         FIG. 3  is a block diagram showing a configuration for storage. 
         FIG. 4  is a conceptual diagram explaining the configuration of a file storage location management table. 
         FIG. 5  is a conceptual diagram explaining the configuration of an available master space management table. 
         FIG. 6  is a conceptual diagram provided for explaining the configuration of an available copy space management table. 
         FIG. 7  is a flowchart illustrating master file write processing steps. 
         FIG. 8  is a flowchart illustrating copy file write processing steps. 
         FIG. 9  is a conceptual diagram explaining master file write processing and copy file write processing. 
     
    
    
     DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS 
     An embodiment of the present invention will be described below with reference to the attached drawings. It should be understood that the present invention is not limited to this embodiment. 
       FIG. 1  shows the configuration of storage system  1  in the present embodiment. The storage system  1  is configured with an archive server  2  (a host computer) and archive storage  3  connected via a predetermined network  4 , such as a LAN (Local Area Network). Also, the storage system  1  is configured with the archive storage  3  and a management server  5  connected via a predetermined network  6 , such as a LAN. 
     The archive server  2  is a computer device equipped with an information processing resource (not shown), such as a CPU (Central Processing Unit) or memory, and is configured with, for example, a personal computer, a workstation, a main frame, or the like. Also, the archive server  2  is provided with information input devices (not shown), such as a keyboard, a switch, a pointing device, and a microphone, etc., and information output devices (not shown), such as a monitor display, and speaker, etc. 
     The archive server  2  sends a write request and file to the archive storage  3 , writes the aforementioned file in the archive storage  3 , and reads out the file written in the archive storage  3  by sending a readout request. 
     The archive storage  3  is provided with a plurality of archive nodes  7  ( 7 A- 7 D) (corresponding to nodes  1 - 4 ) that are information processing devices. Respective archive nodes  7  are configured to interconnect with one another via the network  6 . The archive nodes  7  are configured with servers  8  ( 8 A- 8 D) (corresponding to servers  1 - 4 ) and storage  9  ( 9 A- 9 D) (corresponding to storage  1 - 4 ) connected via a predetermined network, such as a SAN (Storage Area Network). 
     The servers  8  are provided with: software (program)  31  performing archive processing; storage management software  32  performing storage management processing; and a management table  33  used in the archive processing and the storage management processing. 
     The storage  9  is provided with a plurality of HDDs  44  and a power control unit  45 . The storage  9  operates the plurality of HDDs  44  using a RAID (Redundant Arrays of Independent Disks) system. The storage  9  sets one or more logical volumes  72  (hereinafter referred to as the “volume”) in RAID groups  71  (RAID groups  1 - 4 ) that are physical storage areas provided by one or more HDDs  44 . The storage  9  then writes the sent files into this volume  72  on a predetermined-sized block (hereinafter referred to as “logical block”)—basis. 
     The storage  9  respectively assigns unique identifiers (hereinafter referred to as “LUs (Logical Unit numbers)”) to the volumes  72 . The storage  9  uses the combination of this LU and unique numbers (LBA: Logical Block Addresses) respectively assigned to the logical blocks as an address, and performs file input and output by specifying the aforementioned address. 
     Also, the storage  9  consists of RAID groups  71  combined into two groups, namely, a master storage RAID group  10  (consisting of RAID group  1  and RAID group  2 ) in which the sent files (master files) are written, and a copy storage RAID group  11  (consisting of RAID group  3  and RAID group  4 ) in which the copies of the aforementioned files (copy files) are written. The storage  9  keeps the HDD  44  constituting the master storage RAID group  10  (consisting of the RAID group  71 ) constantly in an active state and the HDD  44  constituting the copy storage RAID group  11  (consisting of the RAID group  71 ) usually in a stopped state (or power-saving state (standby mode)). 
     The management server  5  is a computer device equipped with an information processing resource (not shown), such as a CPU (Central Processing Unit) or memory, and is configured with, for example, a lap-top type personal computer, or the like. Also, the management server  5  is provided with information input devices (not shown), such as a keyboard, a switch, a pointing device, and a microphone, etc., and information output devices (not shown), such as a monitor display, and a speaker, etc. 
     The management server  5  retrieves an HDD management table  62  (will be described later below) from the archive storage  3 , and manages the archive storage  3 , namely, the creation of a new RAID group  71  or new volume  72 , etc. 
     Next, the outline of distributed archive processing in the storage system  1  in the present embodiment will be described. Each of the servers  8  communicates with the other by using software  31 , and they send and receive files via the network  6 . Also, when any change happens in the management table  33 , each server  8  sends the changes to another server  8 , so the management table  33  is constantly kept up-to-date. 
     Furthermore, each server  8  manages the available spaces in the RAID groups  71  in each storage  9  in the management table  33 , and constantly checks available spaces in the archive nodes  7  (more specifically, the RAID group  71  in the storage  9 ). Also, each server  8  recognizes whether the RAID group  71  in the storage  9  belongs to the master storage RAID group  10  or the copy storage RAID group  11  based on the management table  33 . 
     The archive server  2  recognizes the archive storage  3  as one large storage pool. Therefore, when writing a file to the archive storage  3 , the archive server  2  sends a write request and file without identifying in which archive nodes  7  a file is to be written. 
     When receiving a write request and file (master file) sent from the archive server  2 , the server  8  (a receiving server  8 ) refer to the management table  33  by using the software  31 , and write files in the volume  72  in the storage  9  in descending order of available space size, and in accordance with redundancy. 
     More specifically, the receiving server  8  specifies the number of copy files to be created depending on redundancy, check available space in the storage  9  by referring to the management table  33 , and determine in which archive node  7  master files and copy files is to be stored. For example, if the redundancy is “3,” the receiving server  8  decides to send master files to, for example, the archive node  7 A whose available space is the largest in the master storage RAID group  10 ; and to send copy files to the archive node  7 C and the archive node  7 D whose available spaces are respectively the first and second largest in the copy storage RAID group  11 . 
     Subsequently, the receiving server  8  sends the master files to the archive node  7 A. The archive node  7 A then writes the master files in a relevant volume  72  in the master storage RAID group  10  in the storage  9 A. 
     Meanwhile, the server  8 C in the archive nodes  7 C sends to the storage  9  a power-on instruction for turning the power of the HDD  44  on at a predetermined time by using storage management software  32 . Incidentally, the power-on instruction is a instruction for turning on the power of the HDD  44  constituting the copy storage RAID group  11  in the storage  9 C in which copy files is to be written. When receiving the power-on instruction, the storage  9 C activates the HDD  44  by turning on the power of the relevant HDD  44  constituting the copy storage RAID group  11  by means of the power control unit  45 . The server  8 C then sends a copy file sending request to the receiving server  8 . 
     When receiving the copy file sending request sent from a server  8 C, the receiving server  8  creates a copy file for the relevant master file, and sends the created copy file to the server  8 C. The server  8 C then writes the copy file in a relevant volume  72  in the copy storage RAID group  11  in the storage  9 C. 
     Subsequently, the server  8 C sends to the storage  9 C a power-off instruction for turning the HDD  44  off by using the storage management software  32 . Incidentally, the power-off instruction is a instruction for turning off the power of the HDD  44  constituting the RAID group  71  in the copy storage RAID group  11  in the storage  9 C in which copy files were written. When receiving the power-off instruction, the storage  9 C stops the HDD  44  by turning off the power of a relevant HDD  44  constituting the copy storage RAID group  11  by means of the power control unit  45 . 
     The receiving server  8 , the server  8 D in the archive nodes  7 D, and the storage  9 D conduct the same processing as that conducted by the above-described receiving server  8 , the server  8 C in the archive nodes  7 C, and the storage  9 C; activate a relevant HDD  44  constituting the copy storage RAID group  11  by means of the power control unit  45 ; write copy files in a relevant volume  72  in the RAID group  71  in the copy storage RAID group  11  in the storage  9 D; and stop an HDD  44  constituting the relevant RAID group  71  by means of the power control unit  45 . 
       FIG. 2  shows the configuration of the servers  8  ( 8 A- 8 D). The servers  8  include an I/O (Input/Output) port  21  for connecting to the network  4 ; a management port  22  for connecting to the network  6 ; processor  23  for controlling all the servers  8 ; and memory  24  for storing a predetermined program and table, and are configured by interconnecting them via a circuit, such as an internal bus, etc. 
     The software  31  for executing archive processing, the storage management software  32  for executing storage management processing, and the management table  33  used in the archive processing and storage management processing are stored in the memory  24 . The management table  33  consists of a file storage location management table  34 , an available master space management table  35 , an available copy space management table  36 , and a RAID group management table  37 . 
     When receiving a file from the archive server  2 , the processor  23 , by executing the software  31 , checks available spaces in each storage  9  with reference to the management table  33 , creates copy files depending on redundancy, and performs the archive processing for writing master files and copy files in a volume  72  in the storage  9  based on available spaces in the master storage RAID group  10  and the copy storage RAID group  11 . 
     At a predetermined time, the processor  23 , by executing the storage management software  32 , performs the storage management processing for activating or stopping the HDD  44  constituting the copy storage RAID group  11  in the storage  9  in which copy files is to be written. 
     The file storage location management table  34  manages the RAID groups  71  in which files sent from the archive server  2  are stored. The available master space management table  35  manages available spaces on the master storage RAID group  10  basis. The available copy space management table  36  manages available spaces on the copy storage RAID group  11  basis. The RAID group management table  37  manages whether the RAID group  71  belongs to the master storage RAID group  10  or the copy storage RAID group  11 . 
     Incidentally, the details of processing performed by the processor  23  by executing the software  31  and the storage management software  32 , and the detailed configurations of the file storage location management table  34 , the available master space management table  35 , and the available copy space management table  36  will be described later below. 
       FIG. 3  shows the configuration of the storage  9  ( 9 A- 9 D). The storage  9  includes: an I/O port  41  for connecting to the server  8  via a predetermined network; a controller  42  for controlling the entire storage  9 ; management memory  43  for storing a predetermined program and table; the HDD  44  for storing a file; and the power control unit  45  for performing power control processing for the HDD  44 , and is configured by interconnecting them via a circuit, such as an internal bus. 
     The controller  42  is internally provided with: a processor  51  standing between the I/O port  41  and the HDD  44  and performing the control within the storage  9 ; and cache memory  52  for temporarily storing files sent and received between the servers  8 . 
     A control program  61  for controlling the storages  9  and the HDD management table  62  are stored in the management memory  43 . The controller  42  performs control processing for sending and receiving data between the I/O port  41  and the HDD  44  by executing the control program  61 . The HDD management table  62  manages each of the HDDs  44 , the RAID groups  71 , and volumes  72 , and manages them in association with one another. 
     Accordingly, in the HDD management table  62 , it is possible to manage the HDDs  44  constituting the RAID groups  71  and volumes  72  in the RAID groups  71 ; and also possible to recognize whether a RAID group  71  belongs to the master storage RAID group  10  or the copy storage RAID group  11 . 
     One or more HDDs  44  constitute the RAID groups  71  (constituting the master storage RAID group  10  and the copy storage RAID group  11 ). When more than one the HDD  44  constitutes the RAID group  71 , the HDD  44  can form a RAID configuration, such as a RAID  1 , a RAID  5 , or the like. Also, the RAID groups  71  are logically divided into one or more volumes  72 . 
     The power control unit  45  activates or stops a relevant HDD  44  in accordance with a power-on instruction or power-off instruction sent from the server  8 . 
       FIG. 4  shows the configuration of the file storage location management table  34 . The file storage location management table  34  consists of “NODE” columns  34 A. The “NODE” columns  34 A are created for each archive node  7 . In the “NODE” columns  34 A, node names uniquely identifying the archive nodes  7  are stored. Also in the “NODE” columns  34 A, “RAID GROUP” columns (RG) are created for each RAID group  71  in the storage  9  in the archive node  7 . In the “RAID GROUP” columns, RAID group names uniquely identifying the RAID group  71  are stored. 
     When a file is sent from the archive server  2 , “FILE” columns are added in the file storage location management table  34 . In the “FILE” columns, file names uniquely identifying a file are stored. 
     When a master file is written in a volume  72  (an HDD  44 ) in the master storage RAID group  10  in the storage  9  which corresponds to the server  8  in which the master file is to be written, “1” is written in a relevant “RAID GROUP” column in the “NODE” columns  34 A in the file storage location management table  34 . 
     Also, when a volume  72  in the copy storage RAID group  11  in the storage  9  which corresponds to the server  8  in which a copy file is to be written is determined, “2” is written in a relevant “RAID GROUP” column in the “NODE” columns  34 A in the file storage location management table  34 . More specifically, “2” is written in a relevant “RAID GROUP” column in the file storage location management table  34  when a copy file is not written in a volume  72  (an HDD  44 ) in the copy storage RAID group  11  in the storage  9  which corresponds to the relevant server  8 , and copy file write processing has not been conducted. 
     Furthermore, when a copy file is written in a volume  72  (an HDD  44 ) in the copy storage RAID group  11  in the storage  9  which corresponds to the server  8  in which a copy file is to be written, “3” is written in a relevant “RAID GROUP” column in he “NODE” columns  34 A in the file storage location management table  34 . 
     Accordingly, master files and RAID groups  71  in which copy files to be written and written copy files should be stored can be managed in the file storage location management table  34 . 
       FIG. 5  shows the configuration of the available master space management table  35 . The available master space management table  35  consists of: “NODE” columns  35 A; “RAID GROUP” columns  35 B; “CURRENT AVAILABLE SPACE” columns  35 C; and “ANTICIPATED AVAILABLE SPACE” columns  35 D. 
     Node names uniquely identifying the archive nodes  7  are stored in the “NODE” columns  35 A. RAID group names uniquely identifying the RAID group  71  (in the master storage RAID group  10 ) in the archive nodes  7  are stored in the “RAID GROUP” columns  35 B. The current available spaces in the RAID groups  71  in the archive nodes  7  are stored in the “CURRENT AVAILABLE SPACE” columns  35 C. The anticipated available spaces at the time of writing a file in the RAID groups  71  in the archive nodes  7  are stored in the “ANTICIPATED AVAILABLE SPACE” columns  35 D. 
       FIG. 6  shows the configuration of the available copy space management table  36 . The available copy space management table  36  consists of: “NODE” columns  36 A; “RAID GROUP” columns  36 B; “CURRENT AVAILABLE SPACE” columns  36 C; and “ANTICIPATED AVAILABLE SPACE” columns  36 D. 
     Node names uniquely identifying the archive nodes  7  are stored in the “NODE” columns  36 A. RAID group names uniquely identifying the RAID group  71  (in the copy storage RAID group  11 ) in the archive nodes  7  are stored in the “RAID GROUP” columns  36 B. The current available spaces in the RAID groups  71  in the archive nodes  7  are stored in the “CURRENT AVAILABLE SPACE” columns  36 C. The anticipated available spaces at the time of writing a file in the RAID groups  71  in the archive nodes  7  are stored in the “ANTICIPATED AVAILABLE SPACE” columns  36 D. 
       FIG. 7  is an example of a flowchart illustrating detailed processing steps performed by the processor  23  in relation to master file writing processing in the receiving server  8  in the storage system  1 . 
     When, for example, receiving a write request and master file sent from the archive server  2 , the processor  23  in the receiving server  8  specifies the number of copy files to be created depending on redundancy; and specifies the archive node  7  whose available space is the largest in the master storage RAID group  10  with reference to the “ANTICIPATED AVAILABLE SPACE” columns  35 D in the available master space management table  35 , in accordance with the master file writing processing steps (RT 1 ) shown in  FIG. 7 , by executing the software  31  (SP 1 ). 
     Subsequently, the processor  23  in the receiving server  8  writes an anticipated available space at the time of writing a master file in the master storage RAID group  10  in the “ANTICIPATED AVAILABLE SPACE” column  35 D, which corresponds to the master storage RAID group  10  in the archive nodes  7  in which the master file is to be written, in the available master space management table  35  (SP 2 ). 
     The processor  23  in the receiving server  8  then designates the master storage RAID group  10  in which the master file is to be written, and sends the master file to the specified archive node  7  (SP 3 ). Incidentally, in the case illustrated in  FIG. 9 , the server  8  in the receiving server  8  and the designated archive node  7  are the same servers  8 , so no master file will be sent. Furthermore, the server  8  in the archive node  7  to which the master file was sent writes the master file in a relevant volume  72  in the master storage RAID group  10  in the storage  9 A (see FIG.  9 ( 1 )). 
     The processor  23  in the receiving server  8  then adds a “FILE” column for the aforementioned master file in the file storage location management table  34 , and writes “1” in the “RAID GROUP” column, which corresponds to the aforementioned “FILE” column, in the master storage RAID group  10  in the archive nodes  7  in which the master file is written (SP 4 ). 
     The processor  23  in the receiving server  8  then writes the available spaces in the master storage RAID group  10  in the archive nodes  7  in which the master file was written in a relevant “CURRENT AVAILABLE SPACE” column  35 C, which corresponds to the master storage RAID group  10  in the relevant archive node  7 , in the available master space management table  35  (SP 5 ). 
     The processor  23  in the receiving server  8  then specifies the number of the archive nodes  7  whose available space is relatively large in the copy storage RAID group  11  equivalent to the number calculated by subtracting 1 from redundancy, with reference to the “ANTICIPATED AVAILABLE SPACE” column  36 D in the available copy space management table  36  (SP 6 ). 
     Incidentally, in a case illustrated in  FIG. 9 , the processor  23  in the receiving server  8  specifies that the redundancy is “3,” and the archive nodes  7 B and the archive nodes  7 C are the archive nodes  7  whose available space is large. 
     The processor  23  in the receiving server  8  then writes “2” in the “RAID GROUP” column, which corresponds to the “FILE” column for the added master file, for the copy storage RAID group  11  in the archive node  7  in which a copy file is to be written in the file storage location management table  34  (SP 7 ). 
     The processor  23  in the receiving server  8  then writes the anticipated available space at the time of writing a copy file in the copy storage RAID group  11  in the “ANTICIPATED AVAILABLE SPACE” column, which corresponds to the copy storage RAID group  11  in the archive node  7  in which the copy file is to be written, in the available copy space management table  36  (SP 8 ). 
     Eventually, the processor  23  in the receiving server  8  terminates the master file writing processing steps RT 1  illustrated in  FIG. 7  (SP 9 ). 
       FIG. 8  is an example of a flowchart illustrating detailed processing steps in the processor  23  in relation to copy file writing processing in each server  8  in the storage system  1 . 
     In existing distributed archive technique, copy files are written in another archive node  7  at the same time master files are written. However, as explained above, according to this technique, the HDD  44  is frequently activated and stopped, so power consumption cannot effectively be reduced. Therefore, in the present invention, copy files are written all at once so as to effectively reduce the power consumption. 
     More specifically, in the storage system  1  in the present invention, copy file writing is not performed when writing a master file, but is performed when a certain interval (e.g. the number of copy files that are not yet written, or a certain time interval) specified by user is passed. Also, in the storage system  1 , the total number of copy files that are not yet written, the total volume of copy files that are not yet written, and the time elapsed since the previous copy file writing processing are held in the local memory, etc., of the processor  23  in the server  8 . In the storage system  1 , any of the above values or more than one of the values are specified by the administrator of the management server  5 , and copy file writing starts when the above value exceeds the specified value. 
     When, for example, any of the total number of copy files that are not yet written, the total volume of copy files that are not yet written, and the elapsed time from the previous copy file writing processing, or more than one of them exceed the value specified by the administrator of the management server  5 , the processor  23  in each server  8  specifies the copy storage RAID group  11  in which a not-yet-written copy file is to be written with reference to the file storage location management table  34 , in accordance with the copy file writing processing steps RT 2  illustrated in  FIG. 8  by running the software  31  (SP 11 ). 
     Incidentally, the processors  23  in the respective servers  8  hold anticipated available spaces written in their “ANTICIPATED AVAILABLE SPACE” columns  36 D in the available copy space management table  36  when starting the copy file writing processing steps RT 2  in the relevant local memory of the processor  23 , or similar. Also, the processors  23  in the respective servers  8  specify the copy storage RAID group  11  whose “RAID GROUP” column in their “NODE” columns  34 A in the file storage location management table  34  is where “2” is written as a copy storage RAID group  11  to which a not-yet-written copy file is to be written. 
     Subsequently, the processors  23  in the respective servers  8  retrieve the HDD management table  62  from the storage  9  by executing the storage management software  32 , retrieve information on the HDD 44  constituting the specified copy storage RAID group  11 , send to the storage  9  a power-on instruction for the HDD  44  constituting the aforementioned copy storage RAID group  11  (SP 12 ). When receiving the power-on instruction, each storage  9  activates the aforementioned HDD  44  by turning on the HDD  44  constituting the relevant copy storage RAID group  11  (see FIG.  9 ( 2 )). 
     When receiving from the storage  9  a report that the HDD  44  constituting the copy storage RAID group is activated, the processors  23  in the respective servers  8  then send a copy file sending instruction to the server  8  (the receiving server  8 ) having the master file of a copy file to be written (SP 13 ). When receiving the copy file sending request sent from the server  8 , the processor  23  in the receiving server  8  creates a copy file of the relevant master file and sends the aforementioned copy file to the server  8 C (see, FIG.  9 ( 3 )). Incidentally, when receiving a master file, the processor  23  in the receiving server  8  may create copy files depending on redundancy, hold them temporarily in a predetermined HDD  44 , etc., and send a relevant copy file when receiving the copy file sending request. By doing so, redundancy can be maintained before copy file writing is completed. 
     When receiving a copy file from the receiving server  8 , the processors  23  in the respective servers  8  then send the copy file to the storage  9 , and write the aforementioned copy file in a relevant volume  72  in the copy storage RAID group  11  (SP 14 ). 
     The processors  23  in the respective servers  8  then write “3” in the “RAID GROUP” columns for the copy storage RAID group  11  in the archive node  7 , in which a copy file is written, in the file storage location management table  34  (i.e., change “2” written in the “RAID GROUP” columns to “3”) (SP 15 ). 
     When all file writing and updating the file storage location management table  34  are complete, the processors  23  in the respective servers  8  recognize the anticipated available spaces held in their local memory as current available paces and write the current available spaces in the relevant “CURRENT AVAILABLE SPACE” columns  36 C in the available copy space management table  36  (SP 16 ). When receiving a power-off instruction, the respective storages  9  stop the HDD  44  by turning off the aforementioned HDD  44  constituting the relevant copy storage RAID group  11  by means of the power control unit  45  (see, FIG.  9 ( 4 )). 
     The processors  23  in the respective servers  8  send to the storages  9  a power-off instruction for the HDD  44  constituting the activated copy storage RAID group by executing the storage management software  32  (SP 17 ). 
     When receiving from the storage  9  a report that the HDD  44  constituting the copy storage RAID group  11  is stopped, the processors  23  in the respective servers  8  terminate the copy file writing processing steps RT 2  shown in  FIG. 8  (SP 17 ). 
     As described above, in the storage system  1 , the HDD  44  constituting the copy storage RAID group is activated at a predetermined time, a copy file is written in a volume  72  in the aforementioned copy storage RAID group  11 , and then the HDD  44  constituting the aforementioned copy storage RAID group  11  is stopped. 
     Accordingly, the HDDs  44  are divided into two groups, namely, the master storage RAID group  10  and the copy storage RAID group  11 , so it is possible to effectively prevent the HDD  44  from being frequently activated and stopped, minimize the running time of the HDD  44  and effectively reduce power consumption. 
     Incidentally, the present embodiment has described a case where the storage system is provided with four archive nodes  7  ( 7 A- 7 D), but the present invention is not limited to this case and may be utilized in a case where, for example, the storage system is provided with more than one of plural archive nodes. 
     Also, the present embodiment has described a case where the servers  8  ( 8 A- 8 D) and the storages  9  ( 9 A- 9 D) are independently provided in the archive nodes  7 , but the present invention is not limited to this case, and may utilize various other configurations where, for example, the archive node is a single archive node that integrates the server  8  and the storage  9 . 
     Furthermore, the present embodiment has described a case where the storage  9  is provided with four RAID groups  71  (consisting of the RAID groups  1 - 4 ), but the present invention is not limited to this case, and may be utilized in a case where, for example, the storage  9  is provided with more than one of plural RAID groups  71 . 
     The present invention can be utilized in a wide variety of storage systems provided with a plurality of archive nodes. 
     While the invention has been described with respect to a limited number of embodiments, those skilled in the art, having benefit of this disclosure, will appreciate that other embodiments can be devised that do not depart from the scope of the invention as disclosed herein. Accordingly, the scope of the invention should be limited only by the attached claims.