Using bandwidth and capacity parameters to control remote copy operations in storage systems

• US 7,577,805 B2
• Filed: 11/01/2004
• Issued: 08/18/2009
• Est. Priority Date: 11/01/2004
• Status: Expired due to Fees

• Current Assignee: Hitachi, Ltd.
• Original Assignee: Hitachi, Ltd.
• Inventors: Yagawa, Yuichi, Amano, Takashi
• Primary Examiner(s): Thai; Tuan V
• Assistant Examiner(s): Li; Zhuo H
• Application Number:
  US10/980,121
• Publication Number:
  US 20060095696A1
• Time in Patent Office: 1,751 Days
• Field of Search: 711/162, 711/100, 711/114, 711/161, 707/204
• US Class Current: 711/161
• CPC Class Codes: G06F 11/1471 involving logging of persistent data for recovery

Abstract

A system is provided for storage of journal data from a primary site to a secondary site with a predefined quality of service. In one implementation, the primary storage system stores information for updating data stored on the primary disk array in the form of a history of updates made to the data. The primary storage system is configured to transfer this journal information to the secondary storage system. The user can specify the quality of service desired using a variety of measures, for example, a recovery point objective or a recovery time objective. In response, a copy manager within one of the storage systems determines the capacity of the various primary and secondary volumes, and determines the copy rate available, typically dependent upon the bandwidth between the primary and secondary systems. The copy manager then copies journal data to the remote site where it is stored.

Claims

1. In a storage system having a primary storage system and a secondary storage system, a method of providing a copy comprising:

recording data in the primary storage system;

at the primary storage system, storing a record of changes made during the step of recording data in the primary storage system;

at the secondary storage system, issuing a request for reading the record of changes made during the step of recording data in the primary storage system;

sending the record of changes made during the step of recording data in the primary storage system, to the secondary storage system;

recording the record of changes made during the step of recording data in the primary storage system, at the secondary storage system; and

using the record of changes made during the step of recording data in the primary storage system to thereby make a copy at the secondary storage system,

wherein prior to the step of recording data in the primary storage system steps are performed comprising;

forming a plurality of journal groups, each journal group including at least one pair of a primary volume from the primary storage system and a secondary volume from the secondary storage system, each journal group further including a primary journal volume for storage of journal data representing record of changes of the at least one primary volume in the journal group and a secondary journal volume for storage of copies of the journal data stored in the primary journal volume, each journal group configured to maintain consistency of data between each pair of the at least one pair of primary volume and secondary volume;

for each of the plurality of journal groups, determining a capacity and a bandwidth for the primary and secondary journal volumes in said each journal group based on a designated quality of service parameter at a level designated for said each journal group; and

for each of the plurality of journal groups, determining a maximum capacity rate for the primary and secondary journal volumes in said each journal group based on the bandwidth and the designated quality of service parameter for said each journal group.

2. A method as in claim 1 further comprising specifying a level of quality of service for the step of recording the record of changes made during the step of recording data in the primary storage system, at the secondary storage system.

3. A method as in claim 2 wherein the step of specifying a level of quality of service comprises assigning priorities to different types of data and using those priorities in the step of using the record of changes made during the step of recording data in the primary storage system to thereby make a copy at the secondary storage system.

4. A method as in claim 3 where prior to the step of at the primary storage system, storing a record of changes made during the step of recording data in the primary storage system, a step is performed to determine the available bandwidth at the primary storage system.

5. A method as in claim 1 wherein prior to the step of recording data in the primary storage system a determination is made of characteristics of a group of storage volumes in the primary and secondary storage systems.

6. A method as in claim 5 wherein the characteristics include capacity of the storage volumes and a rate at which data may be copied.

14. A method as in claim 1 wherein the designated quality of service parameter includes at least one of a recovery time objective (RTO) parameter or a Recovery Point Objective (RPO) parameter.

15. A method as in claim 1 further comprising designating different levels of the quality of service parameter for the plurality of journal groups, so as to provide different maximum capacity rates according to the different levels.

7. In a storage system having a primary storage system and a secondary storage system, a method of providing a copy comprising:

specifying a measure of quality of service;

forming a plurality of journal groups, each journal group including at least one pair of a primary volume from the primary storage system and a secondary volume from the secondary storage system, each journal group further including a primary journal volume for storage of journal data representing record of changes of the at least one primary volume in the journal group and a secondary journal volume for storage of copies of the journal data stored in the primary journal volume;

for each of the plurality of journal groups, determining a capacity of the primary and secondary journal volumes in said each journal group based on a designated quality of service parameter at a level designated for said each journal group;

for each of the plurality of journal groups, determining a bandwidth for copying between the primary journal volume at the primary storage system and the secondary journal volume at the secondary storage system in said each journal group based on the designated quality of service parameter for said each journal group;

for each of the plurality of journal groups, determining a maximum capacity rate for the primary and secondary journal volumes said each journal group based on the bandwidth and the designated quality of service parameter for said each journal group;

recording data in the primary storage system;

preparing a journal of the data recorded in the primary storage system;

transferring the journal of the data recorded in the primary storage system to the secondary storage system and recording the journal of the data at the secondary storage system; and

using the journal recorded at the secondary storage system to create at the secondary storage system a copy of the data recorded in the primary storage system.

16. A method as in claim 7 further comprising designating different levels of the quality of service parameter for the plurality of journal groups, so as to provide different maximum capacity rates according to the different levels.

8. A storage system comprising:

a primary storage system including a first set of storage volumes for storing data; and

a secondary storage system including a second set of storage volumes for storing data;

the primary storage system including

a first storage for storing information about quality of service for various data to be stored at the primary storage system;

a second storage for storing information about a journal group of storage volumes including a primary volume and a primary journal volume in the primary storage system and a secondary volume and a secondary journal volume in the secondary storage system, the primary, primary journal, secondary, and secondary journal volumes forming the journal group of storage volumes;

a third storage for storing information about capacity of the journal group of storage volumes;

a fourth storage for storing information about a bandwidth for copying between the primary and secondary volumes and between the primary journal and secondary journal volumes; and

wherein data is recorded in the primary volume;

a record of changes made to the primary volume is recorded in the primary journal volume;

the record of changes recorded in the secondary journal volume is transferred to the secondary journal volume and recorded in the secondary journal volume;

the record of changes recorded in the secondary journal volume is used to create in the secondary volume a copy of the data recorded in the primary volume;

wherein the primary and secondary journal volumes have a capacity and a bandwidth determined based on a designated quality of service parameter at a level designated for the journal group; and

wherein the primary and secondary journal volumes have a maximum capacity per second and a maximum capacity per cycle determined based on the bandwidth and the designated quality of service parameter for the journal group.

17. A storage system as in claim 8 wherein the designated quality of service parameter includes at least one of a recovery time objective (RTO) parameter or a Recovery Point Objective (RPO) parameter.

18. A storage system as in claim 8,

wherein a plurality of journal groups are formed, each journal group including at least one pair of a primary volume from the primary storage system and a secondary volume from the secondary storage system, each journal group further including a primary journal volume from the primary storage system and a secondary journal volume from the secondary storage system;

and

wherein different levels of the quality of service parameter are designated for the plurality of journal groups, so as to provide different maximum capacity rates according to the different levels.

9. In a storage system having a primary storage system and a secondary storage system, the primary storage system being coupled to a first host and the secondary storage system being coupled to a second host, a method of providing a copy comprising:

recording data in the primary storage system by storing the data in a primary volume;

at the primary storage system, storing in a primary journal volume a record of changes made during the step of recording data in the primary storage system;

at the secondary storage system, issuing a request for reading the record of changes made during the step of recording data in the primary storage system;

from the primary journal volume, sending the record of changes made during the step of recording data in the primary storage system, to the secondary storage system using a communications link;

recording the record of changes made during the step of recording data in the primary storage system, at the secondary storage system, the recording being made in a secondary journal volume; and

using the record of changes made during the step of recording data in the primary storage system to thereby make a copy in a secondary volume of the secondary storage system,

wherein during the step recording the record of changes made during the step of recording data in the primary storage system, at the secondary storage system, the recording being made in a secondary journal volume;

a further step of monitoring a capacity of the secondary journal volume is performed;

wherein prior to said recording data in the primary storage system, said method further comprises;

forming a journal group that includes the primary volume, the primary journal volume, the secondary volume, and the secondary journal volume;

determining a capacity and a bandwidth for the primary and secondary journal volumes based on a designated quality of service parameter at a level designated for the journal group; and

determining a maximum capacity rate for the primary and secondary journal volumes based on the bandwidth and the designated quality of service parameter for the journal group.

10. A method as in claim 9 wherein following the step of using the record of changes a step of deleting the record of changes is performed.

11. A method as in claim 9 wherein queues are used to control writing of the record of changes in the primary and the secondary journals.

12. A method as in claim 9 wherein during the step of storing in a primary journal volume a record of changes made during the step of recording data in the primary storage system a further step of monitoring capacity of the primary journal volume is performed.

19. A method as in claim 9 further comprising:

forming a plurality of journal groups, each journal group including at least one pair of a primary volume from the primary storage system and a secondary volume from the secondary storage system, each journal group further including a primary journal volume for storage of journal data representing record of changes of the at least one primary volume in the journal group and a secondary journal volume for storage of copies of the journal data stored in the primary journal volume; and

designating different levels of the quality of service parameter for the plurality of journal groups, so as to provide different maximum capacity rates according to the different levels.

13. In a storage system having a primary storage system and a secondary storage system, a method of providing a copy comprising:

recording data in the primary storage system;

at the primary storage system, storing a record of changes made during the step of recording data in the primary storage system;

at the secondary storage system, issuing a request for reading the record of changes made during the step of recording data in the primary storage system;

sending the record of changes made during the step of recording data in the primary storage system, to the secondary storage system;

recording the record of changes made during the step of recording data in the primary storage system, at the secondary storage system; and

using the record of changes made during the step of recording data in the primary storage system to thereby make a copy at the secondary storage system,

wherein prior to the step of recording data in the primary storage system said method further comprises;

forming a plurality of journal groups, each journal group including at least one pair of a primary volume from the primary storage system and a secondary volume from the secondary storage system, each journal group further including a primary journal volume for storage of journal data representing record of changes of the at least one primary volume in the journal group and a secondary journal volume for storage of copies of the journal data stored in the primary journal volume;

for each of the plurality of journal groups, determining a capacity and a copy rate for the primary and secondary journal volumes in said each journal group based on a designated quality of service parameter at a level designated for said each journal group; and

for each of the plurality of journal groups, determining a maximum capacity rate for the primary and secondary journal volumes in said each journal group based on the copy rate and the designated quality of service parameter for said each journal group.

20. A method as in claim 13 further comprising designating different levels of the quality of service parameter for the plurality of journal groups, so as to provide different maximum capacity rates according to the different levels.