System and method for migrating data between memories

• US 6,959,370 B2
• Filed: 01/03/2003
• Issued: 10/25/2005
• Est. Priority Date: 01/03/2003
• Status: Expired due to Term

• Current Assignee: Valtrus Innovations Limited (f/k/a Dolya Holdco 9 Limited) (Key Patent Innovations Limited)
• Original Assignee: Hewlett-Packard Development Company, L.P. (HP Inc.)
• Inventors: Shaw, Mark E., Gostin, Gary B.
• Primary Examiner(s): Anderson, Matthew D.
• Application Number:
  US10/336,430
• Publication Number:
  US 20040133756A1
• Time in Patent Office: 1,026 Days
• Field of Search: 711/165, 711141-146, 711/159, 711/160
• US Class Current: 711/165
• CPC Class Codes: G06F 12/08 in hierarchically structured memory systems, e.g. virtual memory systems

Abstract

An embodiment of the invention provides a method for migrating data from one location to another comprising establishing a new memory location under control of a specific memory accessing device. The new memory location being where data, which is being migrated from a first memory location, is to be resident, the specific accessing device taking control of a certain portion of data resident at the first memory location, the control preventing the certain data from being accessed by any device other than the specific accessing device, obtaining, under control of the specific accessing device, a most recent version of the certain data from the first memory location, forwarding the obtained certain data to the new memory location, and when the obtained certain data is forwarded to the new memory location, marking the certain data as being gone from the first memory location such that attempts to access the certain data at the first memory location from a specific accessing device will be redirected back to the accessing device for redirection to the new memory location.

Claims

1. A method for migrating data from one location to another, said method comprising:

establishing a new memory location under control of a specific memory accessing device, said new memory location being where data which is being migrated from a first memory location is to be resident;

said specific accessing device taking control of a certain portion of data resident at said first memory location, said control preventing said certain data from being accessed by any device other than said specific accessing device;

obtaining, under control of said specific accessing device, the most recent version of said certain data from said first memory location;

forwarding said obtained certain data to said new memory location; and

when said obtained certain data is forwarded to said new memory location, marking said certain data as being gone from said first memory location such that attempts to access said certain data at said first memory location from a specific accessing device will be redirected back to said accessing device for redirection to said new memory location such that if said redirected accesses arrive at said new memory location before said forwarded data arrives, then said redirected accesses are prevented until said forwarded data is written to said new memory location.

2. The method of claim 1 wherein said obtained data is forwarded directly from said first memory location to said new memory location.

3. The method of claim 1 wherein said new memory location is established prior to a migration request being received.

4. The method of claim 1 further including:

continuing said control, obtaining, forwarding and marking steps until all the data which is to be migrated from said first memory location have been moved to said new memory location; and

at the conclusion of said continuing step, updating the system so that all memory accessing devices which can access data at first memory location from which data has migrated are directed to said new memory location instead of to prior memory locations in said first memory location.

5. The method of claim 4 further including:

prior to the conclusion of said continuing step, allowing any memory accessing device to full access said first memory location such that data that has not been moved from said first memory location is obtained from said first memory location and such that data which has been moved from said first memory location will be retrieved from said new memory location under control of information supplied by accessing said first memory location.

6. The method of claim 1 wherein continuing said control, obtaining, forwarding and marking steps until all the data which is to be migrated from said first memory location have been moved to said new memory location;

and

tracking, by the said unrelated accessing devices, the progress of the migration such that accesses to data which has not been migrated, or is likely to have not been migrated, are sent to said first memory location, and accesses to data which has been migrated, or is likely to have been migrated, are sent directly to said new memory location.

7. The method of claim 1 wherein said method operates with any one of a plurality of different operating systems and wherein said redirection is accomplished using a standard redirection procedure of the currently functioning operating system.

8. The method of claim 1 further including:

preventing the accessing of data from both said new and old memory locations between the time when said specific accessing device takes control of said first memory location and the time when said data is forwarded to said new memory location.

9. A system for migrating data from one location to another, said system comprising:

a first set of memory locations, said memory locations holding data accessible by at least one accessing device;

a second set of memory locations, said memory locations available for holding data accessible by said at least one accessing device;

means for accessing selective locations within both said first and said second memory locations, said accessing preventing access to said selective memory locations by any other devices;

a transfer path for moving data from selected locations within said first set of memory locations to selected locations within said second set of memory locations; and

means operative when said data is moved into said second set of memory locations for removing said preventing of said access.

10. The system of claim 9 wherein said transfer path is direct from said first set of memory locations to said second set of memory locations.

11. The system of claim 10 further including:

means operative when a request for data is made to said first set of memory locations for providing said data in response to said request and for redirecting said request when said data has been moved.

12. The system of claim 9 further including:

means operative when all of the data which is intended to be moved has been moved from said first set of memory locations for enabling any future access of data which has been moved to be directed initially to a location, of said second set of memory locations where said data is presently being stored.

13. A computer comprising:

an operating system for controlling said computer;

at least one memory having locations therein at which data is stored;

at least one accessing system for obtaining data from said locations within said one or more memories, the manner of said accessing controlled in part by said operating system in accordance with a data storage map;

a system for selecting locations within said at least one memory between which data is to be migrated, said selecting system operable for inhibiting accessing to both to and from locations associated with said data to be migrated while data is in the process of migrating between said to and from locations;

said system further operable after said data has migrated for allowing an accessing system to access data locations in a memory from which data has migrated and to redirect, under control of said operating system and said at least one memory, the location to which said data has migrated; and

said system further operable after all data which is to be migrated has migrated for causing said operating system to modify said such that new data accessing instructions are directed to the memory location to which said data has migrated and not to the previous location of said data.

14. The computer of claim 13 wherein said memory location to which said data is to migrate resides in a memory added to the computer while the said computer is in operation.

15. The computer of claim 13 wherein at least some of said to and from locations are in the same physical memory.

16. The computer of claim 13 wherein said to locations are in a different physical memory of said at least one memory than are said from locations.

17. A method of operating a computer, said method comprising:

enabling an operating system within said computer to control functions of said computer, one such function being the accessing of data from locations within a first memory, said accessing in accordance with a map of data;

adding, while said computer is in operation, an additional memory to said computer, said additional memory having locations therein where data can be stored;

migrating while said computer is in operation, data from said first memory to said additional memory, said migrating occurring in stages, each stage containing portions of data from said first memory; and

while said stages are being migrated, enabling said first memory to redirect to said additional memory any data accesses directed to portions of data which have already migrated and when all of said stages are complete, changing said map so that subsequent data accesses are directed to said additional memory.

18. The method of claim 17 further comprising:

removing from said computer, when all of said stages are complete and while said computer is in operation, said first memory.

19. A method for migrating data from one location to another, said method comprising:

establishing a new memory location under control of a specific memory accessing device, said new memory location being where data which is being migrated from a first memory location is to reside;

selecting under control of said specific accessing device, a certain portion of data resident at said first memory location;

obtaining, under control of said specific accessing device, the most recent version of said certain data from said first memory location, said obtaining causing subsequent accesses by unrelated accessing devices to be redirected back to said unrelated accessing devices for re-issuance to said new memory location;

forwarding, under control of said specific accessing device, the said obtained certain data to said new memory location; and

if said new memory location receives said redirected access from said unrelated accessing devices before receiving said forwarded certain data, then said redirected accesses are prevented until said forwarded data is written to the said new memory location.

20. The method of claim 19 continuing said control, obtaining, forwarding and marking steps until all the data which is to be migrated from said first memory location have been moved to said new memory location;

and

tracking, by the said unrelated accessing devices, the progress of the migration such that accesses to data which has not been migrated, or is likely to have not been migrated, are sent to said first memory location, and accesses to data which has been migrated, or is likely to have been migrated, are sent directly to said new memory location.

21. The method of claim 19 wherein said method operates under control of an intelligence that is separate from any operating system, where said intelligence may or may not require involvement by said operating systems to accomplish said method.

22. A method for migrating data from one location to another, said method comprising:

establishing a new memory location under control of a specific memory accessing device, said new memory location being where data which is being migrated from a first memory location is to reside;

said specific accessing device taking control of a certain portion of data resident at said first memory location, said control preventing said certain data from being accessed by any device other than said specific accessing device;

obtaining, under control of said specific accessing device, the most recent version of said certain data from said first memory location;

forwarding, under control of said specific accessing device, the said obtained certain data to said new memory location; and

after said certain data is received and written into said new memory location, marking said certain data as being gone from said first memory location such that attempts to access said certain data at said first memory location from a specific unrelated accessing device will be redirected back to said unrelated accessing device for redirection to said new memory location.

23. The method of claim 22 continuing said control, obtaining, forwarding and marking steps until all the data which is to be migrated from said first memory location have been moved to said new memory location;

and

tracking, by the said unrelated accessing devices, the progress of the migration such that accesses to data which has not been migrated, or is likely to have not been migrated, are sent to said first memory location, and accesses to data which has been migrated, or is likely to have been migrated, are sent directly to said new memory location.

24. The method of claim 22 wherein said method operates under control of an intelligence that is separate from any operating system, where said intelligence may or may not require involvement by said operating systems to accomplish said method.