NETWORK STORAGE SYSTEM, MANAGEMENT METHOD THEREFOR, AND CONTROL PROGRAM PRODUCT THEREFOR

• US 20080229040A1
• Filed: 03/03/2008
• Published: 09/18/2008
• Est. Priority Date: 03/12/2007
• Status: Active Grant

• Current Assignee: NEC Corporation
• Original Assignee: NEC Corporation
• Inventors: HONMA, KAZUYA
• Granted Patent: US 8,001,323 B2
• Time in Patent Office: Days
• US Class Current: 711/162
• CPC Class Codes: G06F 13/385 for adaptation of a particular data processing system to different peripheral devices
• CPC Class Codes: G06F 3/061 Improving I/O performance
• CPC Class Codes: G06F 3/0632 by initialisation or re-initialisation of storage systems
• CPC Class Codes: G06F 3/067 Distributed or networked storage systems, e.g. storage area networks [SAN], network attached storage [NAS]

Abstract

A storage system, a storage management method, and a control program product are provided. The storage system is improved in comfortability, convenience, and economy by reducing the amount of copies in a storage device in a network storage system, by heightening storage efficiency and increasing an access speed. In a network storage system in which a plurality of client terminals are directly connected to a storage device via a network, the storage device includes an MV logical disk that stores read-only shared data and a BV logical disk from/onto which data specific to each client terminal is read/written. A control unit that controls read/write operations includes, with an access management table, an LDK management table which has a reference logical disk number column used to issue a command to refer to the MV logical disk when data other than the write data is read.

Claims

1. A network storage system in which a plurality of client terminals and a storage device that stores data read and written by the client terminals are directly connected to each other via a network,

the storage device including:

an MV logical disk (MV;

master volume)for storing read-only shared data sharable among the client terminals;

a BV logical disk (BV;

boot volume) from which or onto which specific data correlated with each client terminal is read and written; and

a control unit which controls reading and writing between the logical disks and the client terminals;

wherein

the control unit determines whether a piece of read command data about a read command issued from a client is present in the BV logical disk correlated with each client terminal, and, if the read command data is not present in the BV logical disk, reads the read command data from the MV logical disk, and performs virtual-memory control to send the read command data read therefrom to the client.

2. The network storage system of claim 1, wherein the control unit includes:

an access management table for correlating each client terminal with the BV logical disk; and

an LDK management table provided in parallel with the access management table, for emitting a command to refer to the MV logical disk if the read command data is not present in the BV logical disk; and

wherein

the control unit reads the read command data while referring to the access management table and the LDK management table.

3. The network storage system of claim 2, wherein the LDK management table includes a column used to manage an attribute of the logical disk and a conversion map column used to manage address mapping of write data, in addition to a reference logical disk number column used to refer to the MV logical disk.

4. The network storage system of claim 1, further comprising a cache memory provided in the control unit, for temporarily storing read/write data from the logical disk,

wherein when a read command is emitted from a client, the control unit first determines whether data about the read command is present in the cache memory by use of a data holding function of the cache memory.

5. The network storage system of claim 1, wherein the network is the Internet or LAN that uses an iSCSI protocol, or is SAN that uses a fiber channel protocol.

6. A network storage system in which a plurality of client terminals and a storage device that stores data read and written by the client terminals are directly connected to each other via a network,

the storage device including:

an MV logical disk (MV;

master volume)for storing read-only shared data sharable among the client terminals;

a BV logical disk (BV;

boot volume) from which or onto which specific data correlated with each client terminal is read and written; and

a control means for controlling reading and writing between the logical disks and the client terminals;

wherein

the control means determines whether a piece of read command data about a read command issued from a client is present in the BV logical disk correlated with each client terminal, and, if the read command data is not present in the BV logical disk, reads the read command data from the MV logical disk, and performs virtual-memory control to send the read command data read therefrom to the client.

7. A storage management method for managing a storage device connected to a plurality of client terminals via a network to include an MV logical disk (MV:

master volume) that stores read-only shared data and a BV logical disk (BV;

boot volume) from which or onto which data specific to each client terminal is read and written, the storage management method comprising;

referring to an LDK management table of the BV logical disk correlated with the client terminal;

determining whether a logical address is present in a conversion map column of the LDK management table;

acquiring a physical address from the conversion map and performing a reading or writing operation if the logical address is present in the conversion map column of the LDK management table; and

acquiring an MV number from a reference logical disk number column of the LDK management table and performing a reading or writing operation from the MV logical disk if the logical address is not present in the conversion map column of the LDK management table.

8. The storage management method of claim 7, further comprising temporarily storing read data read from the MV logical disk in the cache memory, thereafter first referring to the cache memory when the MV number is acquired and read from the reference logical disk number column, and reading the MV number from the MV logical disk if an MV is not present therein.

9. A storage control program product for controlling a storage device connected to a plurality of client terminals via a network to include an MV logical disk (MV:

master volume) that stores read-only shared data and a BV logical disk (BV;

boot volume) from which or onto which data specific to each client terminal is read and written, the storage control program product storing a storage control program causing a computer to execute;

a function to refer to an LDK management table of the BV logical disk correlated with each client terminal;

a function to determine whether a logical address is present in a conversion map column of the LDK management table;

a function to acquire a physical address from the conversion map so as to perform a reading or writing operation if the logical address is present in the conversion map column of the LDK management table; and

a function to acquire an MV number from a reference logical disk number column of the LDK management table and then read data thereabout from the MV logical disk if the logical address is not present in the conversion map column of the LDK management table.