Policy based data migration in a hierarchical data storage system

• US 20060101084A1
• Filed: 10/25/2004
• Published: 05/11/2006
• Est. Priority Date: 10/25/2004
• Status: Abandoned Application

• Current Assignee: International Business Machines Corporation
• Original Assignee: International Business Machines Corporation
• Inventors: Peake, Jonathan W., Kishi, Gregory T., Norman, Mark A.
• Application Number:
  US10/972,929
• Publication Number:
  US 20060101084A1
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: G06F 3/0608 Saving storage space on storage systems
• CPC Class Codes: G06F 3/0647 Migration mechanisms
• CPC Class Codes: G06F 3/0682 Tape device
• CPC Class Codes: G06F 3/0685 Hybrid storage combining heterogeneous device types, e.g. hierarchical storage, hybrid arrays
• CPC Class Codes: G06F 3/0686 Libraries, e.g. tape libraries, jukebox

Abstract

A hierarchical data storage system including a policy based migration engine to select a migration policy and migrate data from a first set of removable storage media, such as tape cartridges, to a second set of removable storage media in accordance with the migration policy. The hierarchical data storage system further includes a control unit including a processor, a host interface to couple the processor to a host, a library manager interface to couple the processor to an automated tape library, a storage device interface to couple said processor to a storage device, and a memory unit.

Claims

1. A data storage system comprising:

a processor;

a host interface coupled to said processor; and

a memory unit coupled to said processor, wherein said memory unit comprises;

a storage management engine; and

a policy based migration engine configured to;

determine whether data stored on a first removable storage media satisfies a migration condition of a migration policy, and, if said migration condition is satisfied, cause said data to be migrated to a second removable storage media.

2. The data storage system of claim 1, wherein said policy based migration engine is further configured to:

for each volume of data stored on said first removable storage media, determine if said volume of data satisfies said migration condition.

3. The data storage system of claim 2, wherein said migration policy is at least one of:

a percent of active data migration policy;

a time since last access migration policy;

a time since last data written migration policy; and

a rate of expiration of data migration policy.

4. The data storage system of claim of claim 3, wherein said migration condition of said time since last access migration policy comprises:

if a pre-defined period of time has elapsed since said volume was accessed, said volume is migrated from said first removable storage media to said second removable storage media.

5. The data storage system of claim 3, wherein said migration condition of said time since last data written migration policy comprises:

if a pre-defined period of time has elapsed since data corresponding to said volume was last written on the first removable storage media, said volume is migrated from said first removable storage media to said second removable storage media.

6. The data storage system of claim 3, wherein said migration condition of said rate of expiration of data migration policy comprises:

if a pre-defined period of time has elapsed since a portion of said volume has expired on said first removable storage media, said volume is migrated from said first removable storage media to said second removable storage media.

7. The data storage system of claim 6, wherein said migration condition of said rate of expiration of said data migration policy further comprises:

active data is migrated from said first removable storage media to said second removable storage media if an amount of active data stored on the cartridge is below a pre-defined threshold of active data.

8. The data storage system of claim 3, wherein said migration condition of said percent of active data policy comprises:

if an amount of active data stored on the cartridge is below a pre-defined threshhold of active data, said active data is migrated from said first removable storage media to said second removable storage media.

9. The data storage system of claim 2, wherein said policy based migration engine is further configured to:

define a first pool, said first pool including said first removable storage media; and

define a second pool, said second pool including said second removable storage media.

10. The data storage system of claim 9, wherein said determining comprises:

determining whether data associated with said first pool satisfies said migration condition,

and, if said migration condition is satisfied, cause said data to be migrated to said second pool.

11. The data storage system of claim 9, wherein a process of reclamation is used to migrate said volume from said first removable storage media to said second removable storage media.

12. The data storage system of claim 1, further comprising:

a storage unit coupled to a storage unit interface of said data storage system.

13. The data storage system of claim 1, further comprising:

a database stored in said memory unit, said database including a volume id and a migration policy, wherein said policy based migration engine is configured to analyze said database to determine whether data stored on a first removable storage media satisfies a migration condition of a migration policy.

14. A method of configuring a hierarchical data storage system for conditional data migration, comprising:

accessing a policy based migration engine of said hierarchical data storage system;

selecting a migration policy, said migration policy configured to conditionally copy active data from a first removable storage media to a second removable storage media; and

setting at least one conditional parameter for said migration policy.

15. The method of claim 14, wherein accessing said policy based migration engine comprises:

loading into memory a plurality of computer instructions configured to evaluate said at least one conditional parameter; and

if said conditional parameter is satisfied, said plurality of computer instructions are configured to cause said active data to be copied from said first removable storage media to said second removable storage media.

16. The method of claim 14, wherein said selecting comprises selecting at least one of:

a percent of active data migration policy;

a time since last access migration policy;

a time since last data written migration policy; and

a rate of expiration of data migration policy.

17. The method of claim 16, wherein setting said at least one conditional parameter for said migration policy comprises:

providing to said policy based migration engine a value representing an amount of active data stored on said first removable storage media as a percentage of all data stored on said first removable storage media.

18. The method of claim 16, wherein setting said at least one conditional parameter for said time since last access migration policy comprises:

providing to said policy based migration engine a value representing a period of time, wherein data on said first removable storage media is migrated if said data is not accessed with said period of time.

19. The method of claim 16, wherein setting said at least one conditional parameter for said time since last data written migration policy comprises:

providing to said policy based migration engine a value representing a period of time, wherein data on said first removable storage media is migrated if data has not been written to said first removable storage media with said period of time.

20. The method of claim 16, wherein setting said at least one conditional parameter for said rate of expiration of data migration policy comprises:

providing to said policy based migration engine a value representing a period of time, wherein data on said first removable storage media is migrated if said period of time has elapsed since a portion of said data became expired.

21. The method of claim 14, further comprising:

defining a first pool, said first pool including said first removable storage media;

defining a second pool, said second pool including said second removable storage media;

assigning said migration policy to said first pool; and

if said conditional parameter is satisfied, said plurality of computer instructions are configured to cause said active data to be copied from said first pool to said second pool.

22. A tape library comprising:

a processor;

a plurality of removable storage media, including a first removable storage media and a second removable storage media;

a tape drive;

a plurality of storage bins;

a means for moving said removable storage media between said storage bins and said tape drive;

a host interface coupled to said processor; and

a memory unit coupled to said processor, wherein said memory unit comprises;

a storage management engine; and

a policy based migration engine configured to;

determine whether data stored on a first removable storage media satisfies a migration condition of a migration policy,

and, if said migration condition is satisfied, cause said data to be migrated to a second removable storage media.

23. The tape library of claim 22, further comprising:

a library manager interface coupled to said processor;

a storage unit interface coupled to said processor; and

a control unit, wherein said control unit comprises said memory unit.

24. The tape library of claim 23, wherein said policy based migration engine is further configured to:

for each volume of data on said first removable storage media, determine if said volume of data satisfies said migration condition.

25. The tape library of claim 24, wherein said migration policy includes at least one of:

a percent of active data migration policy;

a time since last access migration policy;

a time since last data written migration policy; and

a rate of expiration of data migration policy.

26. The tape library of claim of claim 25, wherein said migration condition of the time since last access migration policy comprises:

if a pre-defined period of time has elapsed since said volume was accessed, said volume is migrated from said first removable storage media to said second removable storage media.

27. The tape library of claim 25, wherein said migration condition of said time since last data written migration policy comprises:

if a pre-defined period of time has elapsed since data corresponding to said volume was last written on the first removable storage media, said volume is migrated from said first removable storage media to said second removable storage media.

28. The tape library of claim 25, wherein said migration condition of said rate of expiration of data migration policy comprises:

if a pre-defined period of time has elapsed since a portion of said volume has expired on said first removable storage media, said volume is migrated from said first removable storage media to said second removable storage media.

29. The tape library of claim 28, wherein said migration condition of said rate of expiration of said data migration policy further comprises:

active data is migrated from said first removable storage media to said second removable storage media if an amount of active data stored on the cartridge is below a pre-defined threshold of active data.

30. The tape library of claim 25, wherein said policy based migration engine is further configured to:

define a first pool, said first pool including said first removable storage media; and

define a second pool, said second pool including said second removable storage media.

31. The tape library of claim 29, wherein a process of reclamation is used to migrate said volume from said first removable storage media to said second removable storage media.

32. The tape library of claim 22, further comprising:

a storage unit coupled to a storage unit interface of said tape library.

33. The tape library of claim 22, wherein said first removable media is a tape cartridge.

34. A method of migrating data from a first tape cartridge to a second tape cartridge, comprising:

obtaining a migration policy, said migration policy having a migration condition;

determining whether at least one volume on said first tape cartridge satisfies said migration condition; and

if said migration condition is satisfied, copying said at least one volume to said second tape cartridge.

35. The method of claim 34, wherein a hierarchical data storage system includes a plurality of tape cartridges including said first tape cartridge and said second tape cartridge, said method further comprising:

defining a first pool of tape cartridges;

defining a second pool of tape cartridges;

assigning said migration policy to said first pool;

determining whether each volume on each tape cartridge in said first pool satisfies said migration condition; and

if said migration condition is satisfied, copying said volume to at least one cartridge in said second pool.

36. The method of claim 35, wherein said steps are performed as a background process of the hierarchical data storage system.

37. The method of claim of claim 35, wherein said determining step comprises:

determining if a pre-defined period of time has elapsed since said volume has been accessed on said first tape cartridge.

38. The method of claim 35, wherein said determining step comprises:

determining if a pre-defined period of time has elapsed since a portion of said volume has expired on said first tape cartridge.

39. The method of claim 38, wherein said determining step further comprises:

determining if an amount of active data stored on the cartridge is below a pre-defined threshold of active data.

40. The method of claim 35, wherein said determining step comprises:

determining if a pre-defined period of time has elapsed since data corresponding to said volume was last written on said first tape cartridge.

41. The method of claim of claim 35, wherein said determining step comprises:

determining if a pre-defined period of time has elapsed since said volume has been accessed on said first tape cartridge;

determining if a pre-defined period of time has elapsed since data corresponding to said volume was last written on said first tape cartridge; and

determining if a pre-defined period of time has elapsed since a portion of said volume has expired on said first tape cartridge.

42. The method of claim 35, wherein said steps are performed so as to be transparent to a host application utilizing storage on said hierarchical data storage system.

43. The method of claim 35, wherein said determining step comprises:

determining whether each active volume on each tape cartridge in said first pool satisfies said migration condition.

44. A computer program product tangibly embodying a program of machine-readable instructions executable by a processor of a hierarchical data storage system to perform a method of migrating data from a first tape cartridge to a second tape cartridge, the method comprising operations of:

obtaining a migration policy, said migration policy having a migration condition;

determining whether at least one volume on said first tape cartridge satisfies said migration condition; and

if said migration condition is satisfied, copying said at least one volume to said second tape cartridge.

45. The computer program product of claim 44, wherein said hierarchical data storage system includes a plurality of tape cartridges including said first tape cartridge and said second tape cartridge, said method further comprising:

defining a first pool of tape cartridges;

defining a second pool of tape cartridges;

assigning said migration policy to said first pool;

determining whether each volume on each tape cartridge in said first pool satisfies said migration condition; and

if said migration condition is satisfied, copying said volume to at least one cartridge in said second pool.

46. The computer program product of claim 45, wherein said steps are performed as a background process of the hierarchical data storage system.

47. The computer program product of claim of claim 45, wherein said determining step comprises:

determining if a pre-defined period of time has elapsed since said volume has been accessed on said first tape cartridge.

48. The computer program product of claim 45, wherein said determining step comprises:

determining if a pre-defined period of time has elapsed since a portion of said volume has expired on said first tape cartridge.

49. The computer program product of claim 48, wherein said determining step further comprises:

determining if the amount of active data stored on the cartridge is below a pre-defined threshold of active data.

50. The computer program product of claim 45, wherein said determining step comprises:

determining if a pre-defined period of time has elapsed since data corresponding to said volume was last written on said first tape cartridge.

51. The computer program product of claim of claim 45, wherein said determining step comprises:

determining if a pre-defined period of time has elapsed since said volume has been accessed on said first tape cartridge;

determining if a pre-defined period of time has elapsed since data corresponding to said volume was last written on said first tape cartridge; and

determining if a pre-defined period of time has elapsed since a portion of said volume has expired on said first tape cartridge.

52. The computer program product of claim 45, wherein said steps are performed so as to be transparent to a host application utilizing storage on said hierarchical data storage system.

53. The computer program product of claim 45, wherein said determining step comprises:

determining whether each active volume on each tape cartridge in said first pool satisfies said migration condition.

54. The computer program product of claim 45, wherein said instructions are embodied on a storage device of said hierarchical data storage system.

55. A method of migrating data from a plurality of storage devices, comprising:

defining a first logical group containing said plurality of storage devices;

obtaining a migration policy, said migration policy having a migration condition;

determining whether at least one portion of data on said first storage device satisfies said migration condition, wherein said determining comprises at least one of;

determining if a pre-defined period of time has elapsed since said volume has been accessed on said first tape cartridge;

determining if a pre-defined period of time has elapsed since data corresponding to said volume was last written on said first tape cartridge;

determining if a pre-defined period of time has elapsed since a portion of said volume has expired on said first tape cartridge; and

if said migration condition is satisfied, copying said at least one portion of data to a destination storage device.