JP2005352844A - Method for accessing storage and storage system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To prevent a storage system that uses iSCSI techniques from degrading in communication performance when a terminal accessing a storage moves to a geographically different location. <P>SOLUTION: The storage system comprises a communication terminal and a plurality of storages, all of which are interconnected via a network. Some of the plurality of storages 201A, 201B, 201C, 202A, 202B have means for synchronizing data that they retain with the other storages. An access method for use with the storage system in which the communication terminal and the storages are interconnected by an iSCSI protocol on the network includes a step 1 for managing the address information of a group (storage group) of storages that serve as storages to be accessed by the communication terminal and that retain the same data through synchronization; and a step 2 for calculating, using the address information managed in the step 1, the storage closest to the communication terminal from the storage group to which the storages requested by the communication terminal for access belong. The communication terminal is connected to the storage calculated in the step 2. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a storage connection method and a storage system, and more particularly to a technology effective when applied to a storage connection method on a network using iSCSI technology.

  2. Description of the Related Art Conventionally, there are storage systems in which a plurality of storage devices (hereinafter referred to as storage) are installed on a network such as an IP network, and data handled by a terminal connected to the network is stored and held on the storage. Storage systems that connect to the storage over the network have become popular in recent years with the advent of iSCSI technology. The iSCSI technology is a technology that enables SCSI commands and responses to be used on an IP network by encapsulating them in a TCP bucket (see, for example, Non-Patent Document 1).

  Further, in a storage system that connects to the storage through the network, a technique for specifying the storage to which the terminal is connected is required. As the technology for specifying the storage, for example, the information such as the iSCSI name, IP address, and port number of the target storage device such as the access destination (connection destination) is statically transferred to the initiator such as the client terminal as the access source (connection source) (For example, refer nonpatent literature 2). In addition, for example, there is a method in which the initiator holds an IP address and a port number of a target such as an access destination storage or a storage router and issues a SendTargets command through an iSCSI session to inquire the target (for example, , See Non-Patent Document 2.)

In addition to the method described above, for example, there is a method called iSNS (Internet Storage Name Service) as a method for specifying the storage (see, for example, Non-Patent Document 3). In the iSNS, the iSNS server holds information such as the iSCSI name, IP address, and port number of the initiator and the target, and registers and manages the initiator and the target that can be used by the initiator in the same domain. In this method, the initiator sends a service request (Service Request) including its own iSCSI Name to the iSNS server and discovers a target permitted to be used by the initiator.
J. Satran, K. Meth, C. Sapuntzakis, M. Chadalapaka, E. Zeidner, "Internet Small Computer Systems Interface (iSCSI)", [online], April 2004, [searched June 7, 2004], Internet <URL: http://www.ietf.org/rfc/rfc3720.txt> Naotaka Aoki, "Special Feature: Latest IP Storage Technology" iSCSI "Part.2 iSCSI Technical Specifications" [online], 2002/10/5, [Search June 2, 2004], Internet <URL: http: // www .atmarkit.co.jp / fnetwork / tokusyuu / 16iscsi / iscsi02.html> Josh Tseng, Kevin Gibbons, Franco Travostino, Curt Du Laney, Joe Souza, "Internet Storage Name Service (iSNS)", [online], February 2004, [Search June 7, 2004], Internet <URL: http: //www.ietf.org/internet-drafts/draft-ietf-ips-isns-22.txt>

  In a storage system using the iSCSI technology, a plurality of storages are usually distributed and data stored and held in one storage is copied to another storage. That is, when a certain storage is accessed from a certain terminal and the data A in the storage is transferred, the data A is remotely copied to some other storage. At this time, if the storage to which the data A is transferred from the terminal and the storage to which the data A of the storage is remotely copied are collectively referred to as a storage group, the terminal accesses one of the storages in the storage group. Thus, the data A can be read out and processed (edited).

  The storage system can also use a WAN (Wide Area Network). Further, as a terminal used when accessing the storage system, for example, a mobile terminal having high portability such as a notebook PC (Personal Computer) or PDA (Personal Digital Assistance) can be used. Therefore, if the mobile terminal is used, a user accessing the storage can access the storage without being aware of a geographical connection position (location).

  However, the conventional storage specifying method described in the background art can register several candidates for the storage (target) to the client terminal (initiator), but when the initiator connects, There is a problem that one of registered storages (targets) cannot be dynamically selected.

  Briefly describing this problem, for example, it is assumed that there are 10 different storages (targets) on the storage system, and that the terminal (initiator) is permitted to connect to all storages. At this time, also in the conventional specific method, the terminal can be connected to all the ten storages (targets). However, in the conventional specific method, when the terminal is connected to one of the ten storages, it is not possible to dynamically select one storage that satisfies a certain condition. In the conventional specific method, in order to select the one storage, the registration of the other nine targets must be deleted.

  That is, in the conventional storage system, for example, the mobile terminal is used to access a storage in a storage group (first storage), transfer data A, and then move the mobile terminal from a geographically distant place. When trying to read the data A transferred to the storage using the mobile terminal, the mobile terminal can access another storage in the storage group, in other words, a storage different from the first storage that transferred the data A. . However, at this time, for example, there is a problem that, among the storages in the storage group, the storage closest to the place where the mobile terminal is installed cannot be dynamically selected and accessed.

  In the conventional storage system, remote copy between storages in the storage group is generally performed asynchronously. Therefore, for example, after accessing the storage (first storage) of a storage group using the mobile terminal and transferring the data A, the mobile terminal is used to access the storage from a geographically distant place. When trying to read the transferred data A, even if the storage closest to the location where the mobile terminal is installed is selected from among the storages in the storage group and the storage can be accessed, the accessed There is also a problem that there is no guarantee that the data A is remotely copied to the storage.

  As described above, in the conventional storage system, for example, when the mobile terminal is used to access from a location geographically distant from the previously accessed location, the previously accessed storage is accessed. It is common. For this reason, there is a problem that the distance between the mobile terminal and the storage to be accessed becomes long, the communication performance such as a data transmission delay is remarkably deteriorated, and the access performance to the storage may be remarkably deteriorated.

  An object of the present invention is to provide a storage connection method and system capable of preventing a decrease in storage access performance when a storage access terminal moves to a geographically different location in a storage system using iSCSI technology. Is to provide.

  Another object of the present invention is to provide a storage connection method capable of dynamically selecting and accessing the closest storage among storage groups when a terminal accesses the storage in a storage system using the iSCSI technology. And to provide a system.

  The above and other objects and novel features of the present invention will be apparent from the description of this specification and the accompanying drawings.

  The outline of the invention disclosed in the present application will be described as follows.

  (1) A communication terminal and a plurality of storages are connected to each other via a network, and some of the plurality of storages include means for synchronizing data held by itself with other storages, The communication terminal and the storage connection method of the storage system in which the communication terminal and each storage are connected on the network by the iSCSI protocol, the storage terminal being connected to the communication terminal, and the same data by the synchronization Step 1 for managing the address information of a collection (storage group) of storages that hold the data, and using the address information managed in Step 1, the storage groups to which the storage to which the communication terminal requests connection belong. To calculate the storage closest to the communication terminal. And the communication terminal is a storage connection method for connecting to the storage calculated in the step 2.

  (2) A communication terminal and a plurality of storages are connected to each other via a network, and some of the plurality of storages include means for synchronizing data held by itself with other storages, A storage system in which a communication terminal and each storage are connected to each other by the iSCSI protocol on the network, a collection of storages (storage group) that are candidates for storage to which the communication terminal is connected and hold the same data by the synchronization The address management means that manages the address information of the storage device, and the address information managed by the address information management means, the storage terminal to which the communication terminal requests connection is selected from the storage groups to which the communication terminal belongs. And storage calculation means for calculating near storage Storage system to which the terminal is connected.

  (3) A communication terminal and a plurality of storages are connected to each other via a network, and some of the plurality of storages include means for synchronizing data held by itself with other storages, A storage system in which a communication terminal and each storage are connected on the network by the iSCSI protocol, and the communication terminal is a storage candidate to which the communication terminal is connected, and is a storage system that holds the same data by the synchronization. Using address management means for managing address information of a group (storage group) and address information managed by the address information management means, each storage in the storage group to which the storage to which the communication terminal requests connection belongs, Storage that calculates storage closest to the communication terminal A storage system comprising a means out.

  According to the storage connection method of the present invention, when the communication terminal is connected to a storage holding certain data as in the means (1), the storage closest to the communication terminal is selected from the storage group. Calculate and connect to that storage. Therefore, for example, the communication terminal is a mobile terminal having high portability such as a notebook PC, and the data is obtained from a location that is geographically distant from the location connected to the storage in order to store the data that was previously stored. When reading, the closest storage can be dynamically selected and connected to read the data.

  In the storage connection method of (1), in step 1, for example, in addition to the address information of the storage group, for each storage group, information indicating the storage to which the communication terminal was last connected is managed. After the step 2, when the calculated storage is different from the last connected storage, the calculated storage data and the last connected storage data are synchronized with the step 3. It is preferable to connect to the storage calculated in Step 2 after the processing in Step 3. In this way, when the calculated storage is different from the previously connected storage, by synchronizing the data between the calculated storage and the previously connected storage, by connecting the communication terminal to the calculated storage, The problem that the target data does not exist when connected to the calculated storage can be solved.

  In the storage connection method according to (1), the processing in step 1 and step 2 may be performed by a terminal different from the communication terminal connected to the network, or may be performed by the communication terminal. Good. When the storage system is used in a terminal different from the communication terminal, the storage system may be configured as described in the means (2). Further, when the communication terminal is used, the storage system may be configured as described in the means (3).

  In the storage system of (2) or (3), the storage calculation means connects the calculated storage and the last storage when the calculated storage is different from the last storage connected by the communication terminal. It is preferable to provide means for executing synchronization between storages. By doing so, when the calculated storage is different from the previously connected storage as described above, the communication terminal is calculated after the data is synchronized between the calculated storage and the previously connected storage. By connecting to the storage, the problem that the target data does not exist when connected to the calculated storage can be solved.

  In addition, as a method of calculating the storage closest to the communication terminal, an existing method, for example, a method of calculating from the number of hops using the IP address of the communication terminal and the IP address of the storage may be used.

  The data synchronization between the storages may be executed via a terminal such as a storage management terminal provided separately from the storage, or may be directly executed between the storages.

Hereinafter, the present invention will be described in detail together with embodiments (examples) with reference to the drawings.
Note that components having the same function are denoted by the same reference symbols throughout the drawings for describing the embodiments, and the repetitive description thereof is omitted.

  In the storage system of the present invention, when a communication terminal is connected to a storage that holds certain data, the storage closest to the communication terminal is selected from the group of storages (storage group) that can hold the data. Calculate and connect to that storage. Therefore, for example, the communication terminal is a mobile terminal having high portability such as a notebook PC, and the data is obtained from a place that is geographically distant from the place connected to the storage in order to store the previous data. When reading, the closest storage can be dynamically selected and connected to read the data.

  Also, at this time, if the calculated storage is different from the previously connected storage, after synchronizing the data between the calculated storage and the previously connected storage, by connecting the communication terminal to the calculated storage, The problem that the target data does not exist when connected to the calculated storage is solved.

1 and 2 are schematic diagrams showing a schematic configuration of a storage system according to a first embodiment of the present invention. FIG. 1 is a diagram showing a configuration example of a storage system, and FIG. 2 is a diagram showing an example of an address management table. is there.
In FIG. 1, 1A is a first client terminal, 1B is a second client terminal, 201A is a first storage (original storage), 201B is a second storage (first replication storage), and 201C is a third storage (second replication storage). 202A is the fourth storage, 202B is the fifth storage, 3 is the IP network, 4 is the storage management terminal, 401 is the disk control means, 5 is the management server, 501 is the address management means, and 502 is the storage calculation means.

  For example, as shown in FIG. 1, the storage system of the first embodiment includes communication terminals such as a first client terminal 1A and a second client terminal 1B, a first storage 201A, a second storage 201B, a third storage 201C, This is a system in which a plurality of storages such as a fourth storage 202A and a fifth storage 202B are connected to each other via an IP network 3. In the storage system of the first embodiment, as shown in FIG. 1, the storage management terminal 4 including the disk control unit 401, and the management server including the address management unit 501 and the storage calculation unit 502 are provided in the IP network 3. 5 is connected. In the storage system shown in FIG. 1, the positional relationships of the client terminals 1A and 1B, the storages 201A, 201B, 201C, 202A and 202B, the storage management terminal 4, and the management server 5 on FIG. Reflect the actual positional relationship, that is, the geographical positional relationship.

  At this time, each of the client terminals (communication terminals) is assumed to be a terminal that can access the IP network by wired or wireless communication. Each of the client terminals is a terminal that can connect to the storage by using the iSCSI protocol and can read data from the storage or write data to the storage. In the storage system of the first embodiment, the first client terminal 1A is assumed to be a highly portable mobile terminal such as a notebook PC or PDA. Therefore, as shown in FIG. 1, the first client terminal 1A can be connected to the IP network 3 from the vicinity of the first storage 201A, or the IP network 3 from the vicinity of the second storage 201B. It can also be connected to.

  Of the plurality of storages, the first storage 201A, the second storage 201B, and the third storage 201C are storages that hold the same data by synchronization (remote copy). That is, as shown in FIG. 1, when the data A is transferred from the first client terminal 1A to the first storage 201A, for example, the data A held by the first storage 201A is remote copied by the first storage 201A. Copied (replicated) to the second storage 201B and the third storage 201C. Hereinafter, the collection of the first storage 201A, the second storage 201B, and the third storage 201C is referred to as a first storage group.

  Similarly, it is assumed that the fourth storage 202A and the fifth storage are storages that hold the same data by synchronization (remote copy). Hereinafter, the collection of the fourth storage 202A and the fifth storage 202B is referred to as a second storage group.

  The storage management terminal 4 is a terminal that manages data synchronization between the storages of each storage group. At this time, comparison of data between the storages, control of a synchronization command, and the like are performed by the disk control unit 401. In addition, for example, the disk control unit 401 performs processing for setting the data in the storage so that the client terminal can read and write.

  The management server 5 is a server that calculates the storage closest to the client terminal and notifies the client terminal when the client terminal accesses the storage. At this time, the management server 5 manages the address information of the storage group that is a candidate to which the client terminal is connected in the address management means 501. For example, as shown in FIG. 2, the address management unit 501 uses the iSCSI name of the client terminal, the IP address and port number of the storage that is a candidate to be connected to the client terminal, and the iSCSI Name as the ID of the storage group. Holds an associated address management table. Further, as shown in FIG. 2, the address management table has storage connection information indicating which storage is the last storage connected by the client terminal. That is, in the example shown in FIG. 2, the first client terminal 1A can be connected to the first storage 201A, the second storage 201B, and the third storage 201C of the first storage group (storage group ID = 1). The last connected storage is the first storage 201A. Similarly, in the example shown in FIG. 2, the second client terminal 1B includes the first storage 201A and the third storage 201C of the first storage group, and the fourth storage of the second storage group (storage group ID = 2). 202A and the fifth storage 202B can be connected. The storage connected last among the storages of the first storage group is the first storage 201A, and the storage connected last among the storages of the second storage group is the fifth storage. 202B.

  1 and 2 show only two client terminals, the first client terminal 1A and the second client terminal 1B, but in an actual storage system, more client terminals are connected to the storage. Therefore, the address management table is set for all client terminals connectable to the storage system. At this time, the storage permitting the connection of the client terminal may be determined by the administrator of the management server 5 or the user of each client terminal.

  3 and 4 are schematic diagrams for explaining a connection method to the storage in the storage system of the first embodiment, FIG. 3 is a diagram for explaining the preconditions, and FIG. 4 is a diagram illustrating the first client terminal. It is a sequence diagram until it connects to a storage.

  In describing the connection method to the storage in the storage system of the first embodiment, the following conditions are set. First, it is assumed that the first client terminal 1A previously accessed the first storage 201A and stored data A in the first storage 201A as shown in FIG. Then, the first client terminal 1A moves to a location connected to the IP network 3, and as shown in FIG. 1, from a location closer to the second storage 201B than the first storage 201A in terms of geographical location. It is connected to the IP network 3 and tries to read the data A stored in the first storage 201A. The address management table managed by the address management means 501 of the management server 5 is assumed to be a table as shown in FIG.

  At this time, as shown in FIG. 4, the first client terminal 1A first transmits a storage search request including its own iSCSI Name to the management server 5 (step S601).

  When the management server 5 receives the storage search request, the storage calculation unit 502 calculates the storage closest to the first client terminal 1A that transmitted the search request (step S602). In step S602, for example, a client terminal having the iSCSI Name included in the search request is searched and specified using an address management table managed by the address management unit 501. Next, from the storage group belonging to the same storage group from the address information of each storage group associated with the identified client terminal and the IP address of the client terminal that is the source of the storage search request, The storage closest to the first client terminal 1A is calculated. This calculation method is calculated from, for example, the number of hops between the first client terminal 1A and each storage. In the first embodiment, it is assumed that the closest storage is calculated as the second storage 201B. The calculation method using the number of hops is an example of the closest storage calculation method, and may be calculated by other methods.

  When the storage calculating unit 502 calculates the storage closest to the first client terminal 1A in step S602, next, as shown in FIG. 4, the calculated storage is the first client terminal 1A connected last time. It is determined whether the storage is the same as the storage connected last, that is, the storage connected last (step S603). The determination in step S603 is performed based on connection information in the address management table. In this case, according to the precondition, the storage connected last by the first client terminal 1A is the first storage 201A, which is different from the storage calculated in step S602 (second storage 201B).

  If it is determined in step S603 that the calculated storage is different from the storage connected last time, the management server 5 (storage calculation unit 502) performs the calculation for the storage management terminal 4 as shown in FIG. Command to synchronize the data of the previously connected storage and the storage connected last time (step S604). In this case, a command for synchronizing the data in the second storage 201B and the first storage 201A is transmitted.

  The storage management terminal 4 that has received the synchronization command from the management server 5 first acquires, for example, the data structures of the two storages specified by the received command in the disk control means 401 (step S605). . In this case, the disk control unit 401 acquires the data structure of the first storage 201A and the data structure of the second storage 201B.

  Next, the disk control unit 401 compares the acquired data structures of the respective storages 201A and 201B, and determines whether or not they have been synchronized (step S606). At this time, if synchronization is not performed, as shown in FIG. 4, for example, the second storage 201B is instructed to perform data synchronization with the first storage 201A (step S607), and the second storage 201B Data synchronization is executed between the first storage 201A (step S608). When the data synchronization is completed, the second storage 201B transmits an end notification to the storage management terminal 4 (step S609). As a result, for example, even when remote copy is not executed between the first storage 201A and the second storage 201B, the data A stored in the first storage 201A is copied to the second storage 201B ( Copied).

  When it is determined in step S606 that the disk control unit 401 has been synchronized, or when synchronization by the processing of steps S607 to S609 is completed, the disk control unit 401 then stores the first client terminal in the second storage 201B. The 1A is instructed to perform setting such as separation so that data can be written (step S610). When the second storage 201B receives the command of step S610 and the setting is completed, the second storage 201B transmits a setting completion notification to the storage management terminal 4 (step S611).

  When receiving the completion notification from the second storage 201B, the storage management terminal 4 (disk control means 401) transmits a data synchronization completion notification to the management server 5 (step S612).

  The management server 5 (storage calculation unit 502) determines that the storage calculated in step S603 is the same as the storage connected last time, or when the data synchronization by the processing from step S604 to step S612 is completed. Next, as shown in FIG. 4, the storage connection information in the address management table is updated (step S613). In this case, since the storage calculated in the step S602 is the second storage 201B, for example, in the address management table as shown in FIG. 2, the connection information column is checked from the first storage 201A. Change to the second storage 201B.

  The management server 5 calculates the storage closest to the first client terminal 1A (second storage 201B) by the procedure as described above, and stores the second storage 201B and the first storage 201A in the storage management terminal 4. When the data is synchronized and the connection information is updated, the calculated address information of the second storage 201B is returned to the first client terminal 1A (step S614). When the first client terminal 1A that has acquired the address information of the storage to be connected (second storage 201B) in step S614 connects to the second storage 201B, the data A that has already been saved in the first storage 201A is Since the first client terminal 1A has been copied to the second storage 201B, for example, the first client terminal 1A reads the data A stored in the second storage 201B, processes it, and stores (writes) it in the second storage 201B again. Such processing can be performed (step S615).

  As described above, according to the storage system of the first embodiment, when a communication terminal is connected to a storage holding certain data, the storage closest to the communication terminal is selected from the storage groups. And connect to that storage. Therefore, for example, the communication terminal is a mobile terminal having high portability such as a notebook PC, and the data is obtained from a place that is geographically distant from the place connected to the storage in order to store the previous data. When reading, the closest storage can be dynamically selected and connected to read the data.

  Also, at this time, if the calculated storage is different from the previously connected storage, after synchronizing the data between the calculated storage and the previously connected storage, by connecting the communication terminal to the calculated storage, It is possible to prevent a problem that target data does not exist when connected to the calculated storage.

  In the connection method in the storage system of the first embodiment, as shown in FIG. 4, a synchronization command is transmitted to the second storage 201B in the step S607. However, the present invention is not limited to this, and the first storage 201A is not limited thereto. A synchronization command may be transmitted to

  Further, in the connection method in the storage system of the first embodiment, as shown in FIG. 4, the data of the first storage 201A and the second storage 201B are synchronized using the storage management terminal 4, For example, the synchronization command may be transmitted directly to the first storage 201A or the second storage 201B in step S604.

  In the storage system of the first embodiment, for example, the address management table as shown in FIG. 2 is used. However, the address management table is not limited to this, and other information such as the port of the client terminal is used. It may be a table for managing numbers together.

  5 and 6 are schematic diagrams showing a schematic configuration of the storage system according to the second embodiment of the present invention.

  For example, as shown in FIG. 5, the storage system of the second embodiment includes communication terminals such as a first client terminal 1A and a second client terminal 1B, a first storage 201A, a second storage 201B, a third storage 201C, This is a system in which a plurality of storages such as a fourth storage 202A and a fifth storage 202B are connected to each other via an IP network 3. In the storage system of the first embodiment, the storage management terminal 4 including the disk control unit 401 is connected to the IP network 3 as shown in FIG. That is, the storage system of the second embodiment does not have the management server 5 like the storage system described in the first embodiment. In the storage system shown in FIG. 5, the positional relationships of the client terminals 1A, 1B, the storages 201A, 201B, 201C, 202A, 202B, and the storage management terminal 4 in FIG. That is, it reflects the geographical positional relationship.

  In the storage system of the second embodiment, each client terminal (communication terminal) is a terminal that can access the IP network by wired or wireless communication. Each of the client terminals is a terminal that can connect to the storage by using the iSCSI protocol and can read data from the storage or write data to the storage. In the storage system of the second embodiment, the first client terminal 1A includes the address management unit 501 and the storage calculation unit 502, as shown in FIG. As in the second embodiment, when the first client terminal 1A has the address management means 501, the address management table managed by the address management means 501 can be connected to the first client terminal 1A itself. Storage address information may be managed. Therefore, for example, as shown in FIG. 6, if an IP address and port number of a storage that is a candidate to be connected to the client terminal, and an address management table in which an iSCSI name is associated with the ID of the storage group are held. Good. Further, as shown in FIG. 5, the address management table has storage connection information indicating which storage is the last storage connected by the client terminal.

  In the storage system of the second embodiment, the first client terminal 1A is assumed to be a highly portable mobile terminal such as a notebook PC or PDA. Therefore, as shown in FIG. 1, the first client terminal 1A can be connected to the IP network 3 from the vicinity of the first storage 201A, or the IP network 3 from the vicinity of the second storage 201B. It can also be connected to.

  Although not shown, the second client terminal 1B may also include the address management unit 501 and the storage calculation unit 502. Furthermore, the second client terminal 1B may also be the mobile terminal.

  Further, since the configurations and functions of the respective storages 201A, 201B, 201C, 202A, 202B and the storage management terminal 4 in the storage system of the second embodiment are as described in the first embodiment, detailed description thereof is omitted. To do.

  FIG. 7 is a schematic diagram for explaining a connection method to the storage in the storage system of the second embodiment, and is a sequence diagram until the first client terminal connects to the storage.

  In the storage system of the second embodiment, for example, when the first client terminal 1A is connected to the storage of the first storage group (storage group ID = 1), the management server 5 performed in the first embodiment. Processing may be performed by the first client terminal 1A.

  In the following description, as in the first embodiment, the following conditions are set. First, it is assumed that the first client terminal 1A previously accessed the first storage 201A and stored data A in the first storage 201A as shown in FIG. Then, the first client terminal 1A moves to a location connected to the IP network 3, and as shown in FIG. 5, from a location closer to the second storage 201B than the first storage 201A in terms of geographical location. It is connected to the IP network 3 and tries to read the data A stored in the first storage 201A. The address management table managed by the address management means 501 of the management server 5 is assumed to be a table as shown in FIG.

  At this time, as shown in FIG. 7, for example, the first client terminal 1A first uses the address management table managed by the address management means 501 to store the storage to be connected, in other words, the first data A stored therein. The first storage 201A, the second storage 201B, and the third storage 201C belonging to the same storage group as the storage 201A are specified, and the path to each storage is examined (step S600).

  When the first client terminal 1A examines the route to each of the storages, the storage calculating unit 502 next calculates the storage closest to the first client terminal 1A based on the route (step S602). . In the step S602, for example, it is calculated from the number of hops between the first client terminal 1A and each storage. Also in the second embodiment, it is assumed that the closest storage is calculated as the second storage 201B. The calculation method using the number of hops is an example of the closest storage calculation method, and may be calculated by other methods.

  After calculating the storage closest to the first client terminal 1A in the step S602, the storage calculation unit 502 next stores the calculated storage as the first client terminal 1A connected as shown in FIG. It is determined whether the storage is the same as the storage connected last, that is, the storage connected last (step S603). The determination in step S603 is performed based on connection information in the address management table. In this case, the storage connected last by the first client terminal 1A is the first storage 201A due to the preconditions, which is different from the storage (second storage 201B) calculated in step S602.

  If it is determined in step S603 that the calculated storage is different from the storage connected last time, the first client terminal 1A (storage calculation unit 502) sends the storage management terminal 4 to the storage management terminal 4, as shown in FIG. A command is issued to synchronize the data of the calculated storage and the storage connected last time (step S604). In this case, a command for synchronizing the data in the second storage 201B and the first storage 201A is transmitted.

  The storage management terminal 4 that has received the synchronization command from the first client terminal 1A, for example, first acquires the data structures of the two storages specified by the received command in the disk control means 401 (step) S605). In this case, the disk control unit 401 acquires the data structure of the first storage 201A and the data structure of the second storage 201B.

  Next, the disk control unit 401 compares the acquired data structures of the respective storages 201A and 201B, and determines whether or not they have been synchronized (step S606). At this time, if synchronization is not performed, as shown in FIG. 7, for example, the second storage 201B is instructed to perform data synchronization with the first storage 201A (step S607), and the second storage 201B Data synchronization is executed between the first storage 201A (step S608). When the data synchronization is completed, the second storage 201B transmits an end notification to the storage management terminal 4 (step S609). As a result, for example, even when remote copy is not executed between the first storage 201A and the second storage 201B, the data A stored in the first storage 201A is copied to the second storage 201B ( Copied).

  When it is determined in step S606 that the disk control unit 401 has been synchronized, or when synchronization by the processing of steps S607 to S609 is completed, the disk control unit 401 then stores the first client terminal in the second storage 201B. The 1A is instructed to perform setting such as separation so that data can be written (step S610). When the second storage 201B receives the command of step S610 and the setting is completed, the second storage 201B transmits a setting completion notification to the storage management terminal 4 (step S611).

  When the storage management terminal 4 (disk control unit 401) receives the completion notification from the second storage 201B, it sends a data synchronization completion notification to the first client terminal 1A (step S612).

  The management server 5 (storage calculation unit 502) determines that the storage calculated in step S603 is the same as the storage connected last time, or when the data synchronization by the processing from step S604 to step S612 is completed. Next, as shown in FIG. 4, the storage connection information in the address management table is updated (step S613). In this case, since the storage calculated in step S602 is the second storage 201B, for example, in the address management table as shown in FIG. 6, the connection information column is checked from the first storage 201A. Change to the second storage 201B.

  The first client terminal 1A calculates the storage (second storage 201B) closest to the first client terminal 1A according to the procedure described above, and sends the second storage 201B and the first storage to the storage management terminal 4. When the data of 201A is synchronized and the connection information is updated, the second storage 201B is accessed (step S615). When the first client terminal 1A connects to the second storage 201B, the data A already stored in the first storage 201A has been copied to the second storage 201B, so the first client terminal 1A For example, the data A stored in the second storage 201B can be read, processed, and stored (written) in the second storage 201B again.

  As described above, according to the storage system of the second embodiment, when the communication terminal is connected to a storage holding certain data, the storage closest to the communication terminal is selected from the storage groups. And connect to that storage. Therefore, for example, the communication terminal is a mobile terminal having high portability such as a notebook PC, and the data is obtained from a place that is geographically distant from the place connected to the storage in order to store the previous data. When reading, the closest storage can be dynamically selected and connected to read the data.

  Also, at this time, if the calculated storage is different from the previously connected storage, after synchronizing the data between the calculated storage and the previously connected storage, by connecting the communication terminal to the calculated storage, It is possible to prevent a problem that target data does not exist when connected to the calculated storage.

  In the connection method in the storage system of the second embodiment, as shown in FIG. 7, a synchronization command is transmitted to the second storage 201B in the step S607. However, the present invention is not limited to this, and the first storage 201A is not limited thereto. A synchronization command may be transmitted to

  Further, in the connection method in the storage system of the second embodiment, as shown in FIG. 7, the data of the first storage 201A and the second storage 201B are synchronized using the storage management terminal 4, For example, the synchronization command may be transmitted directly to the first storage 201A or the second storage 201B in step S604.

  In the storage system of the second embodiment, for example, the address management table as shown in FIG. 6 is used. However, the address management table is not limited to this, and other information such as the port of the client terminal is used. It may be a table for managing numbers together.

  The present invention has been specifically described above based on the above-described embodiments. However, the present invention is not limited to the above-described embodiments, and various modifications can be made without departing from the scope of the present invention. is there.

  For example, in the first embodiment and the second embodiment, the first client terminal 1A is described as a mobile terminal such as a notebook PC, and the procedure for connecting to the storage has been described. For example, each client terminal is a desktop PC. There may be. The connection method to the storage in the storage system of the present invention is most effective when applied to a client terminal whose connection location to the IP network 3 changes frequently. Even in the client terminal, for example, when the connection location to the IP network 3 changes due to moving or the like, the storage method closest to the new installation location can be automatically calculated and connected by the connection method of the present invention. .

1 is a schematic diagram illustrating a schematic configuration of a storage system according to a first embodiment of the present invention, and illustrates a configuration example of a storage system. 1 is a schematic diagram illustrating a schematic configuration of a storage system according to a first embodiment of the present invention, and illustrates an example of an address management table. FIG. It is a schematic diagram for demonstrating the connection method to the storage in the storage system of a present Example 1, and is a figure for demonstrating a precondition. It is a schematic diagram for demonstrating the connection method to the storage in the storage system of a present Example 1, and is a sequence diagram until a 1st client terminal connects to a storage. It is a schematic diagram which shows schematic structure of the storage system of Example 2 by this invention, and is a figure which shows the structural example of a storage system. It is a schematic diagram which shows schematic structure of the storage system of Example 2 by this invention, and is a figure which shows an example of an address management table. It is a schematic diagram for demonstrating the connection method to the storage in the storage system of a present Example 2, and is a sequence diagram until a 1st client terminal connects to a storage.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1A ... 1st client terminal 1B ... 2nd client terminal 201A ... 1st storage 201B ... 2nd storage 201C ... 3rd storage 202A ... 4th storage 202B ... 5th storage 3 ... IP network 4 ... Storage management terminal 401 ... Disk control Means 5 ... Management server 501 ... Address management means 502 ... Storage calculation means

Claims (7)

A communication terminal and a plurality of storages are connected to each other via a network, and some of the plurality of storages include means for synchronizing data held by itself with other storages, and the communication terminal A method for connecting the storage terminal and the storage in a storage system in which each storage is connected on the network by an iSCSI (Internet Small Computer Systems Interface) protocol,
Managing address information of a collection of storages (hereinafter referred to as storage groups) that are candidates for storage to which the communication terminal is connected and hold the same data by the synchronization; and
Calculating the storage closest to the communication terminal from among the storages of the storage group to which the storage to which the communication terminal requests connection belongs, using the address information managed in step 1;
The storage connection method, wherein the communication terminal is connected to the storage calculated in step 2. In the step 1, in addition to the address information of the storage group, for each storage group, information indicating the storage to which the communication terminal was last connected is managed,
After the step 2, when the calculated storage is different from the last connected storage, the calculated storage data and the last connected storage data are synchronized.
The storage connection method according to claim 1, wherein the communication terminal is connected to the storage calculated in step 2 after the process of step 3.   3. The storage connection method according to claim 1, wherein the processes of Step 1 and Step 2 are performed by a terminal different from the communication terminal connected to the network.   The storage connection method according to claim 1 or 2, wherein the processing of the step 1 and the step 2 is performed by the communication terminal. A communication terminal and a plurality of storages are connected to each other via a network, and some of the plurality of storages include means for synchronizing data held by itself with other storages, and the communication terminal A storage system in which each storage is connected on the network by an iSCSI protocol,
Address management means for managing address information of a collection of storages (hereinafter referred to as storage groups) that are candidates for storage to which the communication terminal is connected and hold the same data by the synchronization;
Storage calculating means for calculating the storage closest to the communication terminal from among the storages of the storage group to which the storage to which the communication terminal requests connection belongs, using the address information managed by the address information management means. A storage system in which a terminal is connected. A communication terminal and a plurality of storages are connected to each other via a network, and some of the plurality of storages include means for synchronizing data held by itself with other storages, and the communication terminal A storage system in which each of the storages is connected on the network by an iSCSI protocol,
The communication terminal is a candidate for storage to which the communication terminal is connected, and address management means for managing address information of a collection of storages that hold the same data by the synchronization (hereinafter referred to as storage group);
Storage calculating means for calculating the storage closest to the communication terminal from among the storages of the storage group to which the storage to which the communication terminal requests connection belongs, using the address information managed by the address information management means. A storage system characterized by that.   The storage calculating means includes means for executing synchronization between the calculated storage and the last connected storage when the calculated storage is different from the storage connected last by the communication terminal. The storage system according to claim 5 or 6.

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