Storage system and storage control device

• US 20060090048A1
• Filed: 12/21/2004
• Published: 04/27/2006
• Est. Priority Date: 10/27/2004
• Status: Abandoned Application

• Current Assignee: Hitachi, Ltd.
• Original Assignee: Hitachi, Ltd.
• Inventors: Okumoto, Katsuhiro, Honma, Hisao, Nakagawa, Yoshihito, Tamura, Kelshi
• Application Number:
  US11/016,806
• Publication Number:
  US 20060090048A1
• Time in Patent Office: Days
• US Class Current: 711/162
• CPC Class Codes: G06F 11/1662 the resynchronized component or unit being a persistent storage device re-synchronization of failed mirror storage G06F11/2082; rebuild or reconstruction of parity RAID storage G06F11/1008
• CPC Class Codes: G06F 11/2071 using a plurality of controllers
• CPC Class Codes: G06F 11/2082 Data synchronisation
• CPC Class Codes: G06F 3/0605 by facilitating the interaction with a user or administrator
• CPC Class Codes: G06F 3/0607 by facilitating the process of upgrading existing storage systems, e.g. for improving compatibility between host and storage device
• CPC Class Codes: G06F 3/065 Replication mechanisms
• CPC Class Codes: G06F 3/0665 at area level, e.g. provisioning of virtual or logical volumes
• CPC Class Codes: G06F 3/067 Distributed or networked storage systems, e.g. storage area networks [SAN], network attached storage [NAS]

Abstract

The present invention makes it possible, by virtualizing an external memory resource as an internal memory resource, to effectively utilize memory resources, and to synchronize the storage contents of a virtualized inner volume and a real inner volume. The first storage device comprises an internal volume and a virtual internal volume. The entity of the virtual internal volume is the external volume of a second storage device. The external volume can be dealt with as a volume inside the first storage device by mapping the external volume in the storage hierarchy of the first storage device. Furthermore, a copying pair can be formed by internal volume and virtual internal volume, and the contents of both volumes can be synchronized.

Claims

1. A storage system which is constructed by communicably connecting a first storage control device and a second storage control device, and which performs data processing in accordance with requests from a higher device, wherein

said first storage control device comprises:

a first real volume;

a first virtual volume which can form a copying pair with said first real volume;

a first control part which respectively controls data communications between said first real volume and said first virtual volume, and said higher device and said second storage control device; and

a synchronizing part which synchronizes the storage contents of said first real volume and the storage contents of said first virtual volume; and

said second storage control device comprises;

a second real volume which is associated with said first virtual volume; and

a second control part which respectively controls data communications between said second real volume, and said higher device and said first storage control device.

2. The storage system according to claim 1, wherein said first storage control device has a first storage device, said second storage control device has a second storage device, said first real volume is connected to said first storage device via an intermediate storage device, and said first virtual volume is connected to said second storage device via a virtual intermediate storage device that is virtually constructed.

3. The storage system according to claim 1, wherein said synchronizing part copies all of the storage contents stored in said first real volume into said first virtual volume.

4. The storage system according to claim 1, wherein said synchronizing part copies all of the storage contents stored in said first virtual volume into said first real volume.

5. The storage system according to claim 1, wherein said synchronizing part copies the differential data between the storage contents in said first real volume and the storage contents in said first virtual volume into said first virtual volume.

6. The storage system according to claim 1, wherein said synchronizing part copies said differential data into said first virtual volume in cases where write requests to said first real volume from said higher device are stopped.

7. The storage system according to claim 5, further comprising a managing device which is communicably connected to said first storage control device and said second storage control device, respectively, wherein said synchronizing part copies said differential data into said first virtual volume in cases where the access attribute of “

write prohibited”

is set in said first real volume by said managing device, and said managing device sets the access attribute of said first real volume as “

read and write possible”

when the copying of said differential data is completed.

8. The storage system according to claim 1, wherein said synchronizing part copies the differential data between the storage contents of said first real volume and the storage contents of said first virtual volume into said first real volume.

9. The storage system according to claim 8, wherein said synchronizing part acquires differential control information relating to said differential data from said second storage control device, reads out said differential data from said second storage control device on the basis of this differential control information, and copies this differential data into said first real volume.

10. The storage system according to claim 8, wherein said synchronizing part copies said differential data into said first real volume in cases where write requests to said second real volume from said higher device are stopped.

11. The storage system according to claim 8, further comprising a managing device which is communicably connected to said first storage control device and said second storage control device, respectively, wherein said synchronizing part copies said differential data into said first real volume in cases where the access attribute of “

write prohibited”

is set in said second real volume by said managing device, and said managing device sets the access attribute of said second real volume as “

read and write possible”

when the copying of said differential data is completed.

12. A storage control device which is communicably connected with a second storage control device and a higher device, this device comprising:

a first real volume;

a first virtual volume which can form a copying pair with said first real volume;

a first control part which respectively controls data communications between said first real volume and said first virtual volume, and said higher device and said second storage control device; and

a synchronizing part which synchronizes the storage contents of said first real volume and the storage contents of said first virtual volume;

wherein said first virtual volume is associated with a second real volume of said second storage control device.

13. The storage control device according to claim 12, wherein said first storage control device has a first storage device, said second storage control device has a second storage device, said first real volume is connected to said first storage device via an intermediate storage device, and said first virtual volume is connected to said second storage device via a virtual intermediate storage device that is virtually constructed.

14. The storage control device according to claim 12, wherein said synchronizing part copies all of the storage contents stored in said first real volume in said first virtual volume.

15. The storage control device according to claim 12, wherein said synchronizing part copies all of the storage contents stored in said first virtual volume into said first real volume.

16. The storage control device according to claim 12, wherein said synchronizing part copies the differential data between the storage contents of said first real volume and the storage contents of said first virtual volume into said first virtual volume.

17. The storage control device according to claim 12, wherein said synchronizing part copies said differential data into said first virtual volume in cases where write requests to said first real volume from said higher device are stopped.

18. A storage system comprising a higher device which is communicably connected to a first storage control device and a second storage control device, and which respectively issues access requests to said first storage control device and said second storage control device, and a managing device which can communicate with said first storage control device and said second storage control device, wherein said first storage control device comprises:

a first storage device which stores data;

an intermediate storage device which is disposed in a storage region of this first storage device;

a first real volume which is disposed in a storage region of this intermediate storage device;

a virtual intermediate storage device which is disposed in a storage region of a second storage device of said second storage control device;

a first virtual volume which is disposed in a storage region of this virtual intermediate storage device;

a higher communications control part which respectively performs data communications between said higher device, and said second storage control device and said managing device;

a lower communications control part which performs data communications with said first storage device;

a memory part which is shared by said higher communications control part and said lower communications control part; and

a mapping table which is stored in said memory part, and which is used to map said second storage device in said virtual intermediate storage device;

wherein said higher communications control part refers to said mapping table and reads out all of the data from said second real volume, and said lower communications control part stores all of this read-out data in said first storage device, in cases where the first full copying mode that copies all of the storage contents stored in said first virtual volume into said first real volume is designated by said managing device, and

said lower communications control part reads out all of the data of said first real volume from said first storage device, and said higher communications control part refers to said mapping table and writes this read-out data into said second real volume, in cases where the second full copying mode that copies all of the storage contents stored in said first real volume into said first virtual volume is designated by said managing device.

19. The storage system according to claim 18,

wherein said first storage control part and said second storage control part respectively hold differential control information that controls the differential data between the storage contents of said first real volume and the storage contents of said first virtual volume,

said lower communications control part reads out said differential data from said first storage device, and said higher communications control part refers to said mapping table and writes this read-out differential data into said second real volume, in cases where the first differential copying mode that copies said differential data into said first virtual volume is designated by said managing device, and

said higher communications control part reads out said differential control information controlled by said second storage control device, refers to this read-out differential control information and said mapping table, and reads out said differential data from said second real volume, and said lower communications control part stores this read-out differential data in said first storage device, in cases where the second differential copying mode that copies said differential data into said first real volume is designated by said managing device.

20. The storage system according to claim 19, wherein said managing device sets the access attribute of said first real volume as “

write prohibited”

prior to the start of said first differential copying in cases where the execution of said first differential copying mode is designated, and sets the access attribute of said first real volume as “

read/write possible”

following the completion of said first differential copying, and

said managing device sets the access attribute of said second real volume as “

write prohibited”

prior to the start of said second differential copying in cases where the execution of said second differential copying mode is designated, and sets the access attribute of said second real volume as “

read/write possible”

following the completion of said second differential copying.