Storage apparatus

• US 7,240,167 B2
• Filed: 07/02/2004
• Issued: 07/03/2007
• Est. Priority Date: 04/26/2004
• Status: Expired due to Fees

• Current Assignee: Google LLC (Alphabet Inc.)
• Original Assignee: Hitachi, Ltd.
• Inventors: Shirogane, Tetsuya, Matsunami, Naoto
• Primary Examiner(s): Bragdon; Reginald
• Assistant Examiner(s): VO, THANH DUC
• Application Number:
  US10/882,366
• Publication Number:
  US 20050240738A1
• Time in Patent Office: 1,096 Days
• Field of Search: None
• US Class Current: 711/148
• CPC Class Codes: G06F 2209/5014 Reservation
• CPC Class Codes: G06F 3/0619 in relation to data integrity, e.g. data losses, bit errors
• CPC Class Codes: G06F 3/062 Securing storage systems
• CPC Class Codes: G06F 3/0637 Permissions
• CPC Class Codes: G06F 3/067 Distributed or networked storage systems, e.g. storage area networks [SAN], network attached storage [NAS]
• CPC Class Codes: G06F 9/5011 the resources being hardware resources other than CPUs, Servers and Terminals
• CPC Class Codes: G06F 9/526 Mutual exclusion algorithms

Abstract

When a storage apparatus receives a write request for a storage area in LU0, an owner access processing unit judges whether write processing for the storage area is restricted with reference to a lock information table. When it is restricted, the owner access processing unit does not perform write processing for the storage area, and, if it is not restricted, the owner access processing unit sets a write processing restriction in a column of the storage area of the lock information table and performs write processing for the storage area. If other storage apparatuses receive the write request for the same area, the owner access processing unit transmits the lock reservation request to restrict write processing for the area of the LU, and if they receive acceptance of the lock reservation request from this storage apparatus, the owner access processing unit performs write processing for the storage area.

Claims

1. A storage apparatus, comprising:

a host side communication part adapted to enable communication with a a storage side communication part adapted to enable communication with at least one other storage apparatus;

a storage device to store data, where the storage device is divided into a plurality of logical unit (LU) storage areas, and where ones of the LU storage areas are further sub-divided into LU storage sub-areas;

an owner information table to store ownership information indicating which storage apparatus manages each LU storage area;

a lock information table to store lock information indicating whether or not write processing is restricted for each of plural LU sub-areas of said storage device; and

a controller adapted to control the communication of said host side communication part and said storage side communication part and adapted to perform access processing for said storage device, while referring to said owner information table and said lock information table;

wherein said controller controls said storage device to store a same data as the at least one other storage apparatus by making said storage side communication part to transmit and receive the data to and from the at least one other storage apparatus, and

wherein, for access requests for a LU storage sub-area owned by said storage apparatus, said controller performs a lock reservation request receiving step for receiving a lock reservation request to restrict the write processing for any LU storage sub-area among said plural LU storage sub-areas from said at least one other storage apparatus by means of said storage side communication part; and

lock reservation request processing step, upon receiving said lock reservation request in said lock reservation request receiving step;

judging whether or not the write processing for the LU storage sub-area indicated by said lock reservation request is restricted with reference to said lock information table;

transmitting rejection of the lock reservation to said at least one other storage apparatus by means of said storage side communication part when the write processing is restricted; and

setting a write processing restriction in a field of said lock information table when the write processing is not restricted, and transmitting acceptance of the lock reservation to said at least one other storage apparatus by means of said storage side communication part;

said controller then performs;

an access request receiving step for receiving a write request to any LU storage sub-area by means of said host side communication part; and

an owner access processing step, upon receiving said write request in said access request receiving step, performs;

judging whether or not the write processing for the LU storage sub-area indicated by said write request is restricted with reference to said lock information table;

not performing the write processing for said LU storage sub-area when the write processing is restricted;

setting a write processing restriction in a field corresponding to said LU storage sub-area of said lock information table and performing the write processing for said LU storage sub-area when the write processing is not restricted; and

a remote copy processing step for transmitting write data with respect to said write request to all other storage apparatuses by means of said storage side communication part when performing the write processing for said LU storage sub-area that is indicated by said write request in said owner access processing step;

wherein, in said access request receiving step, said host side communication part receives a read request for any one of said plural LU storage sub-areas; and

in said owner access processing step, said host side communication part performs read processing for said LU storage sub-area indicated by said read request without reference to said lock information table and transmits the data acquired as a result of said read processing.

2. A storage apparatus according to claim 1,

wherein said storage device has a collection of plural LU storage sub-areas related as a storage area group, managed by said lock information table;

and

said storage device is provided with the owner information table indicating by which storage apparatus the lock information table for each storage area group of said storage device is managed;

wherein said controller performs an owner judgment processing step for judging said write request received in said access request receiving step is the write processing for the LU storage sub-area included in which storage area group with reference to said owner information table;

if the write processing corresponds to the LU storage sub-area included in a storage area group of said lock information table that is managed by its own site, performing said owner access processing step; and

if the write processing corresponds to the LU storage sub-area included in the storage area group of said lock information table that is managed by another storage apparatus, making said storage apparatus side communication part to transmit the lock reservation request to restrict the write request for the LU storage sub-area included in said storage area group to said other storage apparatus managing the lock information of said storage apparatus side communication part;

non-owner access processing step for performing the write processing for said LU storage sub-area that is indicated by said write request when said storage side communication part receives acceptance of a lock reservation for said lock reservation request after transmitting said lock reservation request in said owner judgment processing step; and

lock release request transmitting step for making said storage apparatus side communication part to transmit a lock release request to release an access restriction for said LU storage sub-area to said other storage apparatus after performing the write processing for said LU storage sub-area in said non-owner access processing step.

3. A storage apparatus according to claim 2,

wherein said controller performs a remote copy processing step for transmitting write data with respect to said write request to all other storage apparatuses by means of said storage side communication part, when performing the write processing for said LU storage sub-area that is indicated by said write request in said non-owner access processing step.

4. A storage apparatus according to claim 3,

wherein said controller receives the read request for any one of said plural LU storage sub-areas by means of said host side communication part in said access request receiving step;

and when judging that said read request is a read processing for the LU storage sub-area that is included in the storage area group of said lock information table that is managed by its own site in said owner judgment processing step, said controller performs the read processing for said LU storage sub-area that is indicated by said read request without reference to said lock information table and transmits the data acquired as a result of said read processing in said owner access processing step; and

said controller receives the read request for any one of said plural LU storage sub-areas by means of said host side communication part in said access request receiving step; and

when judging that said read request is read processing for the LU storage sub-area that is included in the storage area group of said lock information table that is managed by the storage apparatus of another site in said owner judgment processing step, said controller performs the read processing for said LU storage sub-area that is indicated by said read request without transmitting said lock reservation request to the storage apparatus of said other site, and transmits data acquired as a result of said read processing in said owner access processing step.

5. A computer-readable storage medium having a program embedded therein for operating a storage apparatus, wherein said storage apparatus comprises:

a storage device, where the storage device is divided into a plurality of logical unit (LU) storage areas, and where ones of the LU storage areas are further sub-divided into a plural LU storage sub-areas;

a host side communication part adapted to enable communication with a host;

a storage side communication part adapted to enable communication with at least one other storage apparatus; and

a controller adapted to control communication of said host side communication part and said storage side communication part, and adapted to enable access processing for said storage device; and

said controller controls plural storage apparatuses to store a same data therein by transmitting and receiving the data stored in said storage device to and from said at least one other storage apparatus;

said program comprising;

ownership determining code referring to an owner information table used to store ownership information indicating which storage apparatus manages each LU storage area;

lock reservation request receiving code that receives a lock reservation request to restrict write processing for any LU storage sub-area among said plural LU storage sub-areas of said storage device, from said at least one other storage apparatus by means of said storage side communication part; and

lock reservation request processing code that, upon receiving said lock reservation request for a LU storage sub-area that is not owned by said storage apparatus;

judges whether or not the write processing for the LU storage sub-area indicated by said lock reservation request is restricted by referencing a lock information table storing lock information indicating whether or not the write processing for said LU storage sub-area is restricted for each of plural LU storage sub-areas of said storage device;

transmits rejection of the lock reservation request to said at least one other storage apparatus by means of said storage side communication part when the write processing is restricted; and

sets the write processing restriction in the field corresponding to said LU storage sub-area of said lock information table when the write processing is not restricted, and transmits acceptance of the lock reservation request to said other storage apparatus by means of said storage side communication part;

access request receiving code that receives a write request for any one of said plural LU storage sub-areas by means of said host side communication part;

owner access processing code that, upon receiving said write request;

judges whether or not write processing for the LU storage sub-area indicated by said write request is restricted with reference to said lock information table by means of said controller, does not perform the write processing for said LU storage sub-area when the write processing is restricted; and

sets the write processing restriction in a field corresponding to said LU storage sub-area of said lock information table and performs the write processing for said LU storage sub-area, when the write processing is not restricted;

wherein said owner access processing code performs a remote copy processing step for transmitting write data with respect to said write request to all other storage apparatuses by means of said storage side communication part, when said controller performs the write processing for said LU storage sub-area that is indicated by said write request;

wherein said controller receives a read request for any one of said plural LU storage sub-areas by means of said host side communication part in said access request receiving step; and

when judging that said read request is read processing for the LU storage sub-area that is included in a storage area group of said lock information table that is managed by its own site in said owner judgment processing step, said controller performs the read processing for said LU storage sub-area that is indicated by said read request without reference to said lock information table and transmits data acquired as a result of said read processing in said owner access processing step.

6. A computer-readable storage medium according to claim 5,

wherein said storage device has a collection of plural LU storage sub-areas related as a storage area group, managed by said lock information table;

wherein said program product comprising;

owner judgment processing code that;

judges whether said write request received in said access request receiving step is the write processing for the LU storage sub-area included in which storage area group with reference to the owner information table indicating by which storage apparatus a lock information table for each storage area group of said storage device is managed;

if the write processing corresponds to the LU storage sub-area included in the storage area group of said lock information table that is managed by its own site, performs said owner access processing step; and

if the write processing corresponds to the LU storage sub-area included in the storage area group of said lock information table that is managed by another storage apparatus, makes said storage apparatus side communication part to transmit the lock reservation request to restrict the write request for the LU storage sub-area included in said storage area group to said other storage apparatus managing the lock information of said storage apparatus side communication part;

non-owner access processing code that performs the write processing for said LU storage sub-area that is indicated by said write request when said storage side communication part receives acceptance of a lock reservation for said lock reservation request after transmitting said lock reservation request in said owner judgment processing step; and

lock release request transmitting code that makes said storage apparatus side communication part to transmit a lock release request to release an access restriction for said LU storage sub-area to said other storage apparatus, after performing the write processing for said LU storage sub-area by said non-owner access processing code.