Migration of newly allocated data to a storage tier

• US 9,372,630 B2
• Filed: 07/09/2014
• Issued: 06/21/2016
• Est. Priority Date: 07/09/2014
• Status: Active Grant

• Current Assignee: International Business Machines Corporation
• Original Assignee: International Business Machines Corporation
• Inventors: Guo, Yong, McNutt, Bruce, Tang, Tao, Xu, Yan
• Primary Examiner(s): YU, JAE UN
• Application Number:
  US14/327,190
• Publication Number:
  US 20160011803A1
• Time in Patent Office: 713 Days
• Field of Search: 711/114
• US Class Current: 1/1
• CPC Class Codes: G06F 3/0611 in relation to response time
• CPC Class Codes: G06F 3/0619 in relation to data integrity, e.g. data losses, bit errors
• CPC Class Codes: G06F 3/0647 Migration mechanisms
• CPC Class Codes: G06F 3/0665 at area level, e.g. provisioning of virtual or logical volumes
• CPC Class Codes: G06F 3/0685 Hybrid storage combining heterogeneous device types, e.g. hierarchical storage, hybrid arrays
• CPC Class Codes: G06F 3/0688 Non-volatile semiconductor memory arrays
• CPC Class Codes: G06F 3/0689 Disk arrays, e.g. RAID, JBOD

Abstract

A method, for migrating newly allocated data into a second storage tier, includes receiving a request to store a data item. The method includes allocating an extent to a first storage tier to store the new data item. The method includes determining whether an extent is newly allocated on the first storage tier. The method includes migrating, by avoiding a learning phase, the newly allocated extent to the second storage tier from the first storage tier.

Claims

1. A method for migrating newly allocated data into a second storage tier comprising:

receiving a request to store a data item;

allocating a physical extent on a first storage tier to store the data item;

monitoring a set of logical extents for a logical extent that is newly allocated;

detecting a logical extent in the set of logical extents that is newly allocated on the first storage tier and that points to the physical extent; and

migrating, in response to the logical extent being newly allocated, the physical extent to the second storage tier from the first storage tier, wherein the second storage tier exhibits a higher performance than the first storage tier.

2. The method of claim 1, further comprising:

communicating, in response to the detecting, a notification that the logical extent is newly allocated.

3. The method of claim 1, wherein the allocating the physical extent includes:

allocating the physical extent to a reserved unallocated space on a thin provision volume of the first storage tier.

4. The method of claim 1, further comprising:

attaching, as part of a write process that allocates the physical extent on the first storage tier, a metadata flag to the logical extent that indicates the logical extent is newly allocated.

5. The method of claim 4, wherein detecting a logical extent in the set of logical extents is newly allocated includes:

scanning a plurality of logical extents at each running cycle for a presence of the metadata flag; and

recording to a memory, in response to the presence of the metadata flag, a logical extent from the plurality of logical extents as being newly allocated.

6. The method of claim 1, wherein the data item is a delivery status of a package related to a customer order.

7. The method of claim 1, further comprising demoting a third physical extent from the SSD storage tier to the HDD storage tier after the detecting and before the migrating.

8. A computer system for migrating newly allocated data into a second storage tier comprising:

a plurality of storage devices arranged into at least a first storage tier and the second storage tier; and

one or more computer processor circuits configured to;

receive a request to store a data item;

allocate a physical extent on a first storage tier to store the data item;

monitor a set of logical extents for a logical extent that is newly allocated;

detect a logical extent in the set of logical extents that is newly allocated on the first storage tier and that points to the physical extent; and

migrate, in response to the logical extent being newly allocated, the physical extent to the second storage tier from the first storage tier wherein the second storage tier exhibits a higher performance than the first storage tier.

9. The computer system of claim 8, wherein the computer processor circuit is configured to detect a logical extent in the set of logical extents that is newly allocated by receiving a notification that the logical extent is newly allocated.

10. The computer system of claim 8, wherein the computer processor circuit is configured to allocate the physical extent by allocating the physical extent to a reserved allocated space on a thin provision volume of the first storage tier.

11. The computer system of claim 8, wherein the computer processor circuit is configured to allocate the data item by attaching, as part of a write process, a metadata flag to the logical extent that indicates the logical extent is newly allocated.

12. The computer system of claim 11, wherein the computer processor circuit is configured to detect a logical extent in the set of logical extents that is newly allocated by:

scanning a plurality of logical extents at each running cycle for a presence of the metadata flag; and

recording to a memory, in response to the presence of the metadata flag, a logical extent from the plurality of logical extents as being newly allocated.

13. The computer system of claim 8, wherein the computer processor circuit is further configured to:

monitor for performance degradation in the second storage tier, wherein performance degradation comprises an increase in read time of a second physical extent in the second storage tier; and

demote cold data from the second storage tier to the first storage tier in response to performance degradation in the second storage, wherein the cold data is data that is not accessed frequently.

19. The computer system of claim 8, wherein the one or more computer processor circuits are further configured to demote a third physical extent from the second storage tier to the first storage tier after the detecting and before the migrating.

14. A computer program product for migrating newly allocated data into a solid-state-drive storage tier from a hard-disk-drive storage tier comprising a computer readable storage device having a computer readable program stored therein, wherein the computer readable program, when executed on a computing device, causes the computing device to:

write data to a first physical extent in the hard-disk-drive (HDD) storage tier;

attach, in response to writing the data, a metadata flag to a logical extent in a set of logical extents on a thin provisioning volume, wherein the logical extent corresponds to the first physical extent and the metadata flag indicates that the first logical extent is allocated;

monitor the set of logical extents on the thin provisioning volume for a metadata flag;

detect, by the monitoring, the metadata flag attached to the logical extent; and

migrate, in response to the detecting, the first physical extent to the solid-state-drive (SSD) storage tier.

15. The computer program product of claim 14, wherein the monitoring comprises scanning the set of logical extents at each running cycle for a presence of a metadata flag.

16. The computer program product of claim 14, wherein the computer readable program causes the computing device to record to a memory, after the detecting and in response to the presence of the metadata flag, that the logical extent from the set of logical extents is newly allocated.

17. The computer program product of claim 14, wherein the computer readable program further causes the computing device to:

monitor for performance degradation in the SDD storage tier, wherein performance degradation comprises an increase in read time of a second physical extent in the SSD storage tier; and

demote cold data from the SDD storage tier to the HDD storage tier in response to performance degradation in the SDD storage, wherein the cold data is data that is not accessed frequently.

18. The computer program of claim 14, wherein computer readable program causes the computing device to demote a third physical extent from the SSD storage tier to the HDD storage tier after the detecting and before the migrating.

20. The computer program product of claim 14, wherein the data is a delivery status of a package related to the customer order.