Using pseudosnapshots for continuous data protection systems to surface a copy of data

• US 7,603,395 B1
• Filed: 05/02/2006
• Issued: 10/13/2009
• Est. Priority Date: 05/02/2006
• Status: Active Grant

• Current Assignee: EMC Corporation (Dell Technologies Inc.)
• Original Assignee: EMC Corporation (Dell Technologies Inc.)
• Inventors: Buchman, Matthew D., Murthy, Venkatesha, Bingham, Scott Forrest, Rokicki, John C., Singhal, Upanshu
• Primary Examiner(s): Wong; Don
• Assistant Examiner(s): Xue; Belinda
• Application Number:
  US11/381,347
• Time in Patent Office: 1,260 Days
• Field of Search: None
• US Class Current: 1/1
• CPC Class Codes: G06F 11/1458 Management of the backup or restore process
• CPC Class Codes: G06F 11/1471 involving logging of persistent data for recovery
• CPC Class Codes: G06F 16/184 implemented as replicated file system
• CPC Class Codes: G06F 2201/84 Using snapshots, i.e. a logical point-in-time copy of the data
• CPC Class Codes: Y10S 707/99955 Archiving or backup

Abstract

Systems and methods for performing replication operations on a continuous data protection system. Exemplary methods include identifying a series of transactions in a continuous data protection system, identifying an event marker indicating a point in time in the series of transactions, copying at least a portion of the series of transactions up until the point in time of the event marker from the continuous data protection system, and presenting the copy of at least a portion of the series of transactions such that the surfaced copy can be read in a subsequent replication operation.

Claims

1. A system for surfacing a copy of data stored in a continuous data protection system, the copy of data used in performing replication operations, the system comprising:

a data tap configured to intercept a series of transactions of a production application and to communicate each of the series of transactions to the continuous data protection system;

the continuous data protection system including a computer and a processor, the continuous data protection system configured to save the series of transactions of the production application, the continuous data protection system configured to allow a point in time view of the series of transactions; and

a replication application communicating with the continuous data protection system, the replication application configured to;

initiate generation of at least one pseudosnapshot of the series of transactions saved on the continuous data protection system;

create at least one event marker that identifies a point in time in the series of transactions in a write journal, each pseudosnapshot associated with at least one event marker, wherein at least one of the at least one pseudosnapshot corresponds to a quiescent state for at least a portion of the series of transactions in the write journal;

present the at least one pseudosnapshot to a user using the at least one event marker, wherein each of the at least one pseudosnapshot is viewed by the user as a snapshot in a graphical user interface, wherein a particular pseudosnapshot is selected for surfacing and wherein the particular pseudosnapshot identifies a dataset that can be reliably surfaced; and

initiate surfacing of a copy of the at least a portion of the series of transactions that were saved before the generation of the selected pseudosnapshot.

2. The system as recited in claim 1, wherein the replication application is located separately from the continuous data protection system.

3. The system as recited in claim 1, wherein the replication application causes the production application to quiesce during the generation of the at least one pseudosnapshot.

4. The system as recited in claim 1, wherein the continuous data protection system is comprised of:

a write journal configured to save the series of transactions; and

at least one volume configured to save a second copy of the surfaced copy.

5. The system as recited in claim 4, wherein the write journal is configured to save the series of transactions from a point in time in which a previous surfaced copy was generated.

6. The system as recited in claim 1, wherein the at least one event marker identifies the point in time after one of the transactions in the series of transactions is saved on the continuous data protection system.

7. The system as recited in claim 6, wherein the at least one event marker is stored in at least one of:

the continuous data protection system;

or

the replication application.

8. The system as recited in claim in 1, further comprising a graphical user interface communicating with at least one of the continuous data protection system or the replication application, the graphical user interface configured to display the at least one pseudosnapshot and allow the user to select the particular pseudosnapshot for surfacing the copy of at least a portion of the series of transactions.

9. In a system for performing replication operations using a continuous data protection system, the continuous data protection system configured to save a series of transactions of a production application, a method for surfacing a copy of data to be used in performing replication operations, the method comprising:

saving a series of transactions of a production application on a continuous data protection system;

generating a plurality of pseudosnapshots from the series of transactions;

creating at least one event marker, wherein each event marker identifies a point in time in the series of transactions of the production application, each pseudosnapshot associated with at least one event marker;

presenting the plurality of pseudosnapshots to a user in a graphical user interface, wherein the plurality of pseudosnapshots correspond to a particular period of time and wherein the plurality of pseudosnapshots appear to the user as traditional snapshots;

identifying a pseudosnapshot from the plurality of pseudosnapshots, the pseudosnapshot relating to a point in time in the series of transactions stored on the continuous data protection system, wherein the pseudosnapshot corresponds to a quiescent state of the series of transactions, wherein the identified pseudosnapshot is associated with an event marker included in the at least one event marker, the event marker identifying a particular point in time after one of the transactions in the series of transactions is saved on the continuous data protection system;

surfacing a copy of at least a portion of the series of transactions saved before the point in time to which the pseudosnapshot relates; and

presenting the surfaced copy such that the surfaced copy can be read in a subsequent replication operation.

10. The method as recited in claim 9, further comprising receiving a selection from the user through the graphical user interface identifying the pseudosnapshot.

11. The method as recited in claim 9, further comprising receiving a selection from the user through the graphical user interface identifying a destination for sending the copy of the transactions.

12. The method as recited in claim 9, further comprising sending the surfaced copy to a destination remote from the continuous data protection system.

13. The method as recited in claim 9, wherein the continuous data protection system is configured to save the series of transactions from a point in time in which a previous surfacing of a copy of transactions occurred.

14. The method as recited in claim 9, wherein surfacing a copy of at least a portion of the series of transactions saved before the point in time to which the pseudosnapshot relates further comprises copying all of the transactions in the series of transactions.

15. A method for surfacing a copy of data in a continuous data protection system, the method comprising:

saving a series of transactions of a production application in the continuous data protection system;

generating a plurality of pseudosnapshots from the series of transactions;

creating at least one event marker, wherein each event marker identifies a point in time in the series of transactions of the production application, each pseudosnapshot associated with at least one event marker;

presenting at least some of the plurality of pseudosnapshots to a user, wherein the plurality of pseudosnapshots appear to the user in a graphical user interface as snapshots and have been identified from a plurality of event markers that were previously created;

identifying a pseudosnapshot from the plurality of pseudosnapshots, the identified pseudosnapshot comprising at least a portion of a series of transactions on the continuous data protection system, wherein the pseudosnapshot is in a quiescent state;

identifying an initial transaction at the beginning of the pseudosnapshot;

identifying a last transaction at the end of the pseudosnapshot;

copying the transactions from the initial transaction of the pseudosnapshot to the last transaction of the pseudosnapshot; and

presenting the copy of the transactions such that the copy can be read in a subsequent replication operation.

16. The method as recited in claim 15, further comprising receiving a selection from a user through a graphical user interface identifying the pseudosnapshot.

17. The method as recited in claim 15, further comprising receiving a selection from a user through a graphical user interface identifying a destination for sending the copy of the transactions.

18. The method as recited in claim 15, wherein identifying a last transaction at the end of the pseudosnapshot comprises identifying an event marker identifying a particular point in time after the last transaction is saved on the continuous data protection system.