DATA PLACEMENT FOR LOSS PROTECTION IN A STORAGE SYSTEM

• US 20140122795A1
• Filed: 10/29/2012
• Published: 05/01/2014
• Est. Priority Date: 10/29/2012
• Status: Active Grant

• Current Assignee: International Business Machines Corporation
• Original Assignee: International Business Machines Corporation
• Inventors: Chambliss, David D.
• Granted Patent: US 9,009,424 B2
• Time in Patent Office: Days
• US Class Current: 711/114
• CPC Class Codes: G06F 11/1076 Parity data used in redundant arrays of independent storages, e.g. in RAID systems
• CPC Class Codes: G06F 11/1451 by selection of backup contents
• CPC Class Codes: G06F 11/2058 using more than 2 mirrored copies
• CPC Class Codes: G06F 11/2069 Management of state, configuration or failover
• CPC Class Codes: G06F 12/16 Protection against loss of memory contents contains no material, see G06F11/00
• CPC Class Codes: G06F 2201/84 Using snapshots, i.e. a logical point-in-time copy of the data
• CPC Class Codes: G06F 3/0619 in relation to data integrity, e.g. data losses, bit errors
• CPC Class Codes: G06F 3/064 Management of blocks
• CPC Class Codes: G06F 3/0673 Single storage device

Abstract

Embodiments of the invention relate to data placement for loss protection in a storage system. One embodiment includes constructing multiple logical compartments. Each logical compartment includes a placement policy including a set of storage placement rules for placement of storage symbols into a set of physical storage containers. A first logical compartment of said plurality of logical compartments is container-overlapped with respect to a second logical compartment of said plurality of logical compartments. The first logical compartment is data loss independent with respect to the second logical compartment. Each of multiple storage volumes is associated with a logical compartment. The storage symbols that represent a data stripe are placed onto physical storage containers in conformity with the placement policy associated with the logical compartment containing the data stripe.

Claims

1. A method of data placement for loss protection in a storage system comprising:

constructing a plurality of logical compartments, each logical compartment comprising a placement policy including a set of storage placement rules for placement of storage symbols into a set of physical storage containers, wherein a first logical compartment of said plurality of logical compartments is container-overlapped with respect to a second logical compartment of said plurality of logical compartments, and said first logical compartment is data loss independent with respect to said second logical compartment;

associating each of a plurality of storage volumes with a logical compartment; and

placing the storage symbols that represent a data stripe onto physical storage containers in conformity with the placement policy associated with the logical compartment containing the data stripe.

2. The method of claim 1, wherein said first logical compartment further being majority-container-overlapped with respect to said second logical compartment.

3. The method of claim 1, wherein said first logical compartment further is fully container-overlapped with respect to said second logical compartment.

4. The method of claim 1, further comprising migrating or reconstructing storage symbols for a stripe into new physical storage containers in conformance with the placement policy that applies to the stripe.

5. The method of claim 4, further comprising migrating or reconstructing storage symbols for a stripe into new physical storage containers for conforming to a change in the placement policy that applies to the stripe.

6. The method of claim 1, wherein said first logical compartment is associated with a first plurality of disjoint container subsets, and containing as a compartmentation policy the intra-subset placements of all container subsets, and said second logical compartment is associated with a second plurality of disjoint container subsets, and containing as compartmentation policy the intra-subset placements of all its container subsets, and wherein said first logical compartment having a property of limited intersection with said second logical compartment.

7. The method of claim 6, said first plurality of disjoint container subsets and said second plurality of disjoint container subsets is constructed by grid sectioning.

8. The method of claim 1, further comprising generating and storing a placement map.

9. A computer program product for loss protection in a storage system, the computer program product comprising:

a computer readable storage medium having computer readable program code embodied therewith, the computer readable program code comprising;

computer readable program code configured to construct a plurality of logical compartments, wherein each logical compartment comprising a placement policy including a set of storage placement rules for placement of storage symbols into a set of physical storage containers, wherein a first logical compartment of the plurality of logical compartments is container-overlapped with respect to a second logical compartment of the plurality of logical compartments, and said first logical compartment is data loss independent with respect to said second logical compartment;

computer readable program code configured to associate each of a plurality of storage volumes with a particular logical compartment; and

computer readable program code configured to place the storage symbols that represent a data stripe onto physical storage containers in conformity with the placement policy associated with the logical compartment containing the data stripe.

10. The computer program product of claim 9, wherein said first logical compartment further is majority-container-overlapped with respect to said second logical compartment.

11. The computer program product of claim 9, wherein said first logical compartment further is fully container-overlapped with respect to said second logical compartment.

12. The computer program product of claim 9, further comprising generating and storing a placement map as metadata.

13. The computer program product of claim 10, further comprising migrating or reconstructing storage symbols for a stripe into new physical storage containers in conformance with the placement policy that applies to the stripe.

14. The computer program product of claim 9, further comprising migrating or reconstructing storage symbols for a stripe into new physical storage containers for conforming to a change in the placement policy that applies to the stripe.

15. The computer program product of claim 13, wherein said first logical compartment is associated with a first plurality of disjoint container subsets, and containing as a compartmentation policy the intra-subset placements of all container subsets, and said second logical compartment is associated with a second plurality of disjoint container subsets, and containing as compartmentation policy the intra-subset placements of all its container subsets, and wherein said first logical compartment having a property of limited intersection with said second logical compartment.

16. The computer program product of claim 15, wherein said first plurality of disjoint container subsets and said second plurality of disjoint container subsets is constructed by grid sectioning

17. A storage system comprising:

a storage controller that constructs a plurality of logical compartments in one or more memory devices, each logical compartment comprising a placement policy including a set of storage placement rules for placement of storage symbols into a set of physical storage containers in the storage system, wherein a first logical compartment of the plurality of storage compartments is container-overlapped with respect to a second logical compartment of the plurality of storage compartments, and said first logical compartment is data loss independent with respect to said second logical compartment;

the storage controller further associates each of a plurality of storage volumes with a logical compartment, and places the storage symbols that represent a data stripe onto physical storage containers in conformity with the placement policy associated with the logical compartment containing the data stripe.

18. The storage system of claim 17, wherein said first logical compartment further is majority-container-overlapped with respect to said second logical compartment, and said first logical compartment further is fully container-overlapped with respect to said second logical compartment.

19. The storage system of claim 18, that the storage controller further migrates or reconstructs storage symbols for a stripe into new physical storage containers in conformance with the placement policy that applies to the stripe.

20. The storage system of claim 19, wherein the storage controller further migrates or reconstructs storage symbols for a stripe into new physical storage containers for conforming to a change in the placement policy that applies to the stripe, said first logical compartment is associated with a first plurality of disjoint container subsets, and containing as a compartmentation policy the intra-subset placements of all container subsets, and said second logical compartment is associated with a second plurality of disjoint container subsets, and containing as compartmentation policy the intra-subset placements of all its container subsets, and wherein said first logical compartment having a property of limited intersection with said second logical compartment, and said first plurality of disjoint container subsets and said second plurality of disjoint container subsets is constructed by grid sectioning.