Methods and systems for replicating an expandable storage volume

• US 9,043,567 B1
• Filed: 03/28/2012
• Issued: 05/26/2015
• Est. Priority Date: 03/28/2012
• Status: Expired due to Fees

• Current Assignee: NetApp, Inc.
• Original Assignee: NetApp, Inc.
• Inventors: Jennings, Logan R., Modukuri, Kiran K.
• Primary Examiner(s): Rutz, Jared
• Assistant Examiner(s): EDOUARD, JEAN C
• Application Number:
  US13/433,170
• Time in Patent Office: 1,154 Days
• US Class Current: 711/162
• CPC Class Codes: G06F 11/1448 Management of the data involved in backup or backup restore
• CPC Class Codes: G06F 11/1451 by selection of backup contents
• CPC Class Codes: G06F 11/1456 Hardware arrangements for backup
• CPC Class Codes: G06F 11/1464 for networked environments
• CPC Class Codes: G06F 11/1469 Backup restoration techniques
• CPC Class Codes: G06F 11/2069 Management of state, configuration or failover
• CPC Class Codes: G06F 11/2071 using a plurality of controllers
• CPC Class Codes: G06F 11/2074 Asynchronous techniques
• CPC Class Codes: G06F 11/2082 Data synchronisation
• CPC Class Codes: G06F 12/00 Accessing, addressing or allocating within memory systems or architectures digital input from, or digital output to record carriers, e.g. to disk storage units, G06F3/06
• CPC Class Codes: G06F 12/0292 using tables or multilevel address translation means G06F12/023 takes precedence; address translation in virtual memory systems G06F12/10
• CPC Class Codes: G06F 12/1009 using page tables, e.g. page table structures
• CPC Class Codes: G06F 12/16 Protection against loss of memory contents contains no material, see G06F11/00
• CPC Class Codes: G06F 13/00 Interconnection of, or transfer of information or other signals between, memories, input/output devices or central processing units interface circuits for specific input/output devices G06F3/00 ; multiprogram control therefor G06F9/46; multiprocessor systems G06F15/16
• CPC Class Codes: G06F 16/00 Information retrieval; Database structures therefor; File system structures therefor
• CPC Class Codes: G06F 16/128 Details of file system snapshots on the file-level, e.g. snapshot creation, administration, deletion use of snapshots for error detection or correction G06F11/14, G06F11/16
• CPC Class Codes: G06F 16/1824 implemented using Network-attached Storage [NAS] architecture distributed or networked storage systems G06F3/067; protocols for distributed storage of data in a network H04L67/1097
• CPC Class Codes: G06F 16/1827 Management specifically adapted to NAS management of storage area networks [SAN] G06F3/067
• CPC Class Codes: G06F 16/27 Replication, distribution or synchronisation of data between databases or within a distributed database system; Distributed database system architectures therefor
• CPC Class Codes: G06F 16/275 Synchronous replication
• CPC Class Codes: G06F 16/284 : Relational databases
• CPC Class Codes: G06F 16/951 : Indexing; Web crawling techniques
• CPC Class Codes: G06F 2201/82 : Solving problems relating to consistency
• CPC Class Codes: G06F 2201/84 : Using snapshots, i.e. a logical point-in-time copy of the data
• 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 3/0631 : by allocating resources to storage systems
• CPC Class Codes: G06F 3/065 : Replication mechanisms
• CPC Class Codes: G06F 3/0662 : Virtualisation aspects
• 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

Machine implemented method and system for generating a disaster recovery copy of an expandable storage volume having a namespace for storing information for accessing data objects stored at a data constituent volume is provided. A transfer operation for transferring a point in time copy of the expandable storage volume from a first location to a second location is generated. Information regarding the expandable storage volume from the first location is retrieved and a destination expandable storage volume is resized to match components of the expandable storage volume at the first location. Thereafter, the point in time copy of the expandable storage volume is transferred from the first location to the second location and configuration information regarding the point in time copy is copied from the first location to the second location.

Claims

1. A machine implemented method, comprising:

creating a snapshot of each component of a source expandable storage volume that increases and decreases in size based on usage by initiating a logical fence for a namespace volume, an object location system (OLS) data store and then for a plurality of data constituent storage volumes of the source expandable storage volume and removing the logical fence in a reverse order after the snapshot is taken;

wherein the namespace volume is for storing information to access data containers using a directory path address, the OLS data store is used to retrieve data containers using a location identifier and an object identifier without having to use the directory path address of the namespace volume and the plurality of data constituent volumes are used for storing data containers; and

wherein the logical fence prevents any read and write requests in the snapshot of the expandable storage volume generated after the logical fence is initiated;

generating a transfer operation for transferring the snapshot of each component of the source expandable storage volume from a first location to a second location;

retrieving information regarding the source expandable storage volume from the first location;

resizing the destination expandable storage volume at the second location to match components of the source expandable storage volume at the first location;

transferring the snapshot of each component of the source expandable storage volume from the first location to the second location;

copying configuration information regarding the snapshots from the first location to the second location; and

updating a data structure for storing information regarding the transferred snapshot of the expandable storage volume, where the data structure enables presenting snapshots of each of the components of the source expandable storage volume as a single logical object, while each individual snapshot is also accessible as an individual logical entity.

2. The method of claim 1, wherein the expandable storage volume with the plurality of data constituent volumes is managed by at least two different storage system nodes.

3. The method of claim 1, wherein the namespace volume stores a directory namespace having a directory entry associated with a data object stored at one of the data constituent volumes.

4. The method of claim 3, wherein the directory namespace is a network attached storage (NAS) path namespace of a storage system.

5. The method of claim 4, wherein the directory entry stores a pointer to a redirector file that includes an object locator of the data object.

6. The method of claim 1, further comprising:

presenting the transferred snapshot of the source expandable storage volume as a disaster recovery copy from the second location for reading and writing information; and

resizing the source expandable storage volume at the first location to match the destination expandable storage volume at the second location.

7. The method of claim 6, further comprising:

re-synchronizing the source expandable storage volume with the destination storage volume after the first location becomes available and the disaster recovery copy is no longer used.

8. The machine implemented method of claim 1, further comprising:

establishing a mirroring relationship between components of the source expandable storage volume at the first location with components of the destination expandable storage volume, where the mirroring relationship enables replication of the components of the source expandable storage volume that increases and decreases in size based on usage.

9. A non-transitory, machine readable storage medium having stored thereon instructions for performing a method, comprising machine executable code which when executed by at least one machine, causes the machine to:

create a snapshot of each component of a source expandable storage volume that increases and decreases in size based on usage by initiating a logical fence for a namespace volume, an object location system (OLS) data store and then for a plurality of data constituent storage volumes of the source expandable storage volume and removing the logical fence in a reverse order after the snapshot is taken;

wherein the namespace volume is for storing information to access data containers using a directory path address, the OLS data store is used to retrieve data containers using a location identifier and an object identifier without having to use the directory path address of the namespace volume and the plurality of data constituent volumes are used for storing data containers; and

wherein the logical fence prevents any read and write requests in the snapshot of the expandable storage volume generated after the logical fence is initiated;

generate a transfer operation for transferring the snapshot of each component of the source expandable storage volume from a first location to a second location;

retrieve information regarding the source expandable storage volume from the first location;

resize the destination expandable storage volume at the second location to match components of the source expandable storage volume at the first location;

transfer the snapshot of each component of the source expandable storage volume from the first location to the second location;

copy configuration information regarding the snapshots from the first location to the second location; and

update a data structure for storing information regarding the transferred snapshot of the expandable storage volume, where the data structure enables presenting snapshots of each of the components of the source expandable storage volume as a single logical object, while each individual snapshot is also accessible as an individual logical entity.

10. The storage medium of claim 9, wherein the expandable storage volume with the plurality of data constituent volumes is managed by at least two different storage system nodes.

11. The storage medium of claim 9, wherein the namespace volume stores a directory namespace having a directory entry associated with a data object stored at one of the data constituent volumes.

12. The storage medium of claim 11, wherein the directory namespace is a network attached storage (NAS) path namespace of a storage system.

13. The storage medium of claim 12, wherein the directory entry stores a pointer to a redirector file that includes an object locator of the data object.

14. The storage medium of claim 9, the machine executable code further causes the machine to:

present the transferred snapshot of the source expandable storage volume as a disaster recovery copy from the second location for reading and writing information; and

resize the source expandable storage volume at the first location to match the destination expandable storage volume at the second location.

15. The storage medium of claim 13, the machine executable code further causes the machine to:

re-synchronize the source expandable storage volume with the destination storage volume after the first location becomes available and the disaster recovery copy is no longer used.

16. A system, comprising:

a memory with machine readable medium comprising machine executable code having stored thereon instructions; and

a processor module coupled to the memory configured to execute the machine executable code to;

create a snapshot of each component of a source expandable storage volume that increases and decreases in size based on usage by initiating a logical fence for a namespace volume, an object location system (OLS) data store and then for a plurality of data constituent storage volumes of the source expandable storage volume and removing the logical fence in a reverse order after the snapshot is taken;

wherein the namespace volume is for storing information to access data containers using a directory path address, the OLS data store is used to retrieve data containers using a location identifier and an object identifier without having to use the directory path address of the namespace volume and the plurality of data constituent volumes are used for storing data containers; and

wherein the logical fence prevents any read and write requests in the snapshot of the expandable storage volume generated after the logical fence is initiated;

generate a transfer operation for transferring the snapshot of each component of the source expandable storage volume from a first location to a second location;

retrieve information regarding the source expandable storage volume from the first location;

resize the destination expandable storage volume at the second location to match components of the source expandable storage volume at the first location;

transfer the snapshot of each component of the source expandable storage volume from the first location to the second location;

copy configuration information regarding the snapshots from the first location to the second location; and

update a data structure for storing information regarding the transferred snapshot of the expandable storage volume, where the data structure enables presenting snapshots of each of the components of the source expandable storage volume as a single logical object, while each individual snapshot is also accessible as an individual logical entity.

17. The system of claim 16, wherein the expandable storage volume with the plurality of data constituent volumes is managed by at least two different storage system nodes.

18. The system of claim 16, wherein the namespace volume stores a directory namespace having a directory entry associated with a data object stored at one of the data constituent volumes.

19. The system of claim 16, where the machine executable code further causes the machine to:

present the transferred snapshot of the source expandable storage volume as a disaster recovery copy from the second location for reading and writing information;

resize the source expandable storage volume at the first location to match the destination expandable storage volume at the second location; and

re-synchronize the source expandable storage volume with the destination storage volume after the first location becomes available and the disaster recovery copy is no longer used.

20. The system of claim 16, where the machine executable code further causes the machine to:

establish a mirroring relationship between components of the source expandable storage volume at the first location with components of the destination expandable storage volume, where the mirroring relationship enables replication of the components of the source expandable storage volume that increases and decreases in size based on usage.