Hierarchy of a structure of a volume

• US 20080172542A1
• Filed: 01/16/2007
• Published: 07/17/2008
• Est. Priority Date: 01/16/2007
• Status: Active Grant

• Current Assignee: Avago Technologies General IP PTE Limited (Broadcom, Inc.)
• Original Assignee: LSI Logic Corporation (Broadcom, Inc.)
• Inventors: Kaushik, Shyam
• Granted Patent: US 8,037,262 B2
• Time in Patent Office: Days
• US Class Current: 711/202
• CPC Class Codes: G06F 11/2094 Redundant storage or storage space G06F11/2056 takes precedence
• CPC Class Codes: G06F 3/0605 by facilitating the interaction with a user or administrator
• CPC Class Codes: G06F 3/0608 Saving storage space on storage systems
• CPC Class Codes: G06F 3/0617 in relation to availability
• 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 3/0689 Disk arrays, e.g. RAID, JBOD

Abstract

A method, apparatus and system of a hierarchy of a structure of a volume is disclosed. In one embodiment, a system includes a physical volume, a structure to provide a mapping to a location of a data segment of the physical volume that may include a table having a hierarchy, a logical volume management module to define a logical volume as an arrangement of the physical volume, a snapshot module that may automatically generate a point-in-time image of the logical volume, may prompt the logical volume management module to create and insert a first table and a second table into the hierarchy of the structure, the first table may provide a set of updates to the logical volume, the second table may provide a set of updates to the point-in-time image, and a data processing system to perform a write IO operation and a read IO operation.

Claims

1. A system comprising

a physical volume;

a structure to provide a mapping to a location of a data segment of the physical volume including at least one table having a hierarchy, wherein each table to indicate a set of updates of the physical volume during a time period;

a logical volume management module to define a logical volume as an arrangement of the physical volume;

a snapshot module to automatically generate a point-in-time image of the logical volume and to prompt the logical volume management module to create a first table and a second table and to insert the first table and the second table into the hierarchy of the structure, the first table to provide a set of updates to the logical volume, the second table to provide a set of updates to the point-in-time image, thereby the structure to provide a set of common mappings of the point-in-time image and the logical volume; and

a data processing system to perform a write IO operation and a read IO operation.

2. The system of claim 1, further comprising a remote replication module of a remote site to process and to archive the point-in-time image of the snapshot module to prevent damage to the data during a crisis of the physical volume to enable recovery of the physical volume.

3. The system of claim 2, further comprising a file system to provide a directory of files and to mount on at least one of the point-in-time image to define a snapshot volume and the logical volume, such that the snapshot volume to enable testing, maintenance and administration of the file system and the logical volume.

4. The system of claim 3, wherein the hierarchy of the at least one table of the structure to be organized in the hierarchy according to rank determined by recency of each of the at least one table.

5. A method comprising:

storing data of an enterprise in a physical volume;

instantiating a logical volume to provide an arrangement of the data of the physical volume;

providing a hierarchical structure to indicate mappings between an address of the data of the logical volume and an address of the data of the physical volume;

generating a point-in-time image of the logical volume;

creating a first table to track modifications to the logical volume, associating the first table with the logical volume, and incorporating the first table into the hierarchical structure; and

creating a second table to track modifications to the point-in-time image, associating the second table with the point-in-time image, and incorporating the second table into the hierarchical structure.

6. The method of claim 5, further comprising organizing at least one table of the hierarchical structure according to a length of time since creation such that the first table and the second table to rank highest.

7. The method of claim 6, further comprising reorganizing the at least one table of the hierarchical structure after removing a table of the at least one table.

8. The method of claim 7, further comprising writing a data to a logical address of the logical volume by referencing a used entry of the logical address of the first table of the hierarchical structure, extracting a location information including a corresponding physical address of the physical volume, overwriting a previous data of the corresponding physical address, and updating the first table to indicate a mapping of the data.

9. The method of claim 8, further comprising writing the data to the logical address of the logical volume by referencing an unused entry of the address of the first table of the hierarchical structure, allocating a data segment of the physical volume having a physical address, loading the data into the data segment, and updating the first table to indicate the mapping of the physical address of the data.

10. The method of claim 9, further comprising writing the data to an address of the point-in-time image by referencing an used entry of the address of the second table of the hierarchical structure, extracting the location information including the corresponding physical address of the physical volume, overwriting a previous data of the corresponding physical address, and updating the second table to indicate the mapping of the data.

11. The method of claim 10, further comprising writing the data to the address of the point-in-time image by referencing the unused entry of the address of the second table of the hierarchical structure, allocating a data segment having the physical address of the physical volume, loading the data into the data segment, and updating the second table to indicate the mapping of the physical address of the data.

12. The method of claim 11, further comprising reading the data of the logical address of the logical volume by referencing an used entry of the logical address in the table associated with the logical volume of the hierarchical structure, extracting the location information including the corresponding physical address of the physical volume, and retrieving the data of the corresponding physical address.

13. The method of claim 12, further comprising reading the data of the logical address of the logical volume by referencing an unused entry of the logical address in each table associated with the logical volume of the hierarchical structure, determining an absence of the mapping of the logical address, and returning a zero-filled buffer.

14. The method of claim 13, further comprising reading the data from the address of the point-in-time image by referencing an used entry of the address in the table associated with the point-in-time image of the hierarchical structure, extracting the location information including the corresponding physical address of the physical volume, and retrieving the data of the corresponding physical address.

15. The method of claim 14, further comprising reading the data of the address of the point-in-time image by referencing the unused entry of the address in each table associated with the logical volume of the hierarchical structure, determining the absence of the mapping of the logical address, and communicating the absence to a logical volume management module.

16. The method of claim 15, further comprising processing and archiving the point-in-time image in a remote site to prevent corruption and to enable recovery of the logical volume during a crisis.

17. The method of claim 16, further comprising mounting a file system on the point-in-time image to define a snapshot volume to enable testing, maintenance, and administration of the logical volume and the file system.

18. The method of claim 5, further comprising a form of a machine-readable medium embodying a set of instructions that, when executed by a machine, causes the machine to perform the method of claim 5.

19. An apparatus comprising:

a printed circuit board to enable a data processing system to communicate and interoperate with a storage device;

a physical volume;

a logical volume to provide an array of data of the physical volume;

a point-in-time image of the logical volume; and

a structure of the printed circuit board having a hierarchy of at least one table to provide mapped locations of data of the physical volume, each table to indicate updates during a specific time period of at least one of the logical volume and the point-in-time image.

20. The apparatus of claim 19, wherein the structure to organize the hierarchy of the at least one table by moment of creation such that an earliest table to rank lowest and a latest table to rank highest.

21. The apparatus of claim 20, wherein the structure further including a common table to provide mappings to the physical volume common to the point-in-time image and the logical volume, a first table to provide updates to the logical volume, and a second table to provide updates to the point-in-time image such that the first table and the second table to branch from the common table in the hierarchy of the structure.

22. The apparatus of claim 21, further comprising a garbage collector application to copy a used entry of an address of a lower ranked table associated with at least one of the logical volume and the point-in-time image to an unused entry of the address of a higher ranked table of the at least one of the logical volume and the point-in-time image.