File replication

1. A computer program product for use in replication comprising:

a non-transitory computer readable medium encoded with computer executable program code for replication of data, the code configured to enable the execution of:

intercepting an Input/Output (IO) for a file at an application layer at the production site at a splitter;

determining at the splitter if the IO corresponds to a file that is being replicated including examining the IO for a file ID; and

based on a determination the file is being replicated, sending the IO to a first data recovery appliance (DPA);

recording the IO corresponding to the file in a journal;

determining that the IO is a command to increase a file size; and

determining if the increased data is known; and

based on a negative determination, pausing replication and marking the unknown area in a delta marker stream and resuming replication and re-synchronizing the data.

2. The computer program product of claim 1 wherein the file ID is located in a SCSI command of the IO and where the code is further enabled for execution of:

sending the IO from the first data recovery appliance to a second data recovery appliance; and

sending the IO to a target on the production site.

3. The code of claim 1 further enabled for execution of:

reading the IO from the journal; and

creating an UNDO for the IO; and

applying the data to the file.

4. The code of claim 3 further enabled for execution of:

determining that the IO is a command to create a file;

adding the file to a consistency group;

notifying the splitter to split the IO for the file; and

creating the file at the replication site.

5. The code of claim 3 further enabled for execution of:

determining that the IO is a command to delete a file;

copying the data in the file to an undo journal;

adding a create file to the undo journal; and

deleting the file.

6. The code of claim 3 further enabled for execution of:

determining that the IO is a command to delete a file;

moving the file to a temporary directory; and

noting moved file's temporary location in the undo journal.

7. The code of claim 6 further enabled for execution of:

freeing data from the undo journal based on the undo journal being full and based on the temporary directory being full.

8. The code of claim 7 further enabled for execution of:

deleting files from the temporary directory based on the deletion of pointers to the file from the undo journal.

9. The code of claim 3 further enabled for execution of:

determining that the IO is a command to decrease a file size;

noting the file size should be increased to the original in the undo;

moving decreased data into the undo journal, and decreasing the file size.

10. The code of claim 1 wherein the DPA is a virtual machine.

11. The code of claim 1 further enabling for execution of:

tracking changes made to a replicated file;

if replication of the file stops due to a problem, reading the changes made during the problem at the DPA and sending the changes to a second DPA.

12. A computer implemented method comprising:

intercepting an IO for a file at a splitter at an application layer at the production site;

determining at the splitter if the file is being replicated including examining the IO for a file ID;

based on a determination the file is being replicated, sending the IO to a first data recovery

appliance (DPA) and recording the IO corresponding to the file in a journal;

determining that the IO is a command to increase a file size; and

determining if the increased data is known; and

based on a negative determination, pausing replication and marking the unknown area in a delta marker stream and resuming replication and re-synchronizing the data.

13. The method of claim 12 wherein the file ID is located in a SCSI command of the IO and wherein the method further comprises:

sending the IO from the first data recovery appliance to a second data recovery appliance:

and send the IO to a target on the production site.

14. The method of claim 12 further comprising:

reading the IO from the journal; and

creating an UNDO for the IO; and applying the data to the file.

15. The method of claim 14 further comprising:

determining that the IO is a command to create a file;

adding the file to a consistency group;

notifying the splitter to split the IO for the file; and

creating the file at the replication site.

16. The method of claim 14 further comprising:

determining that the IO is a command to delete a file;

copying the data in the file to an undo journal;

adding a create file to the undo journal; and

deleting the file.

17. The method claim 12 wherein the DPA is a virtual machine.

18. The system of claim 17 wherein the DPA is a virtual machine.

19. A system for data protection, the system comprising:

a production site, the production site comprising a logical storage medium;

a replication site, the replication site comprising a logical storage medium;

a first data protection appliance; and

computer-executable logic operating in memory, wherein the computer-executable program logic is configured for execution of:

intercepting an IO for a file at a splitter at an application layer at the production site;

determining at the splitter if the file is being replicated including examining the IO for a file ID;

based on a determination the file is being replicated, sending the IO to a the data recovery appliance (DPA) and recording the IO corresponding to the file in a journal;

determining that the IO is a command to increase a file size; and

determining if the increased data is known; and

based on a negative determination, pausing replication and marking the unknown area in a delta marker stream and resuming replication and re-synchronizing the data.

20. The system of claim 19 wherein the file ID is located in a SCSI command of the IO and wherein the computer executable logic is further configured for execution of:

sending the IO from the first data recovery appliance to a second data recovery appliance; and

send the IO to a target on the production site.

21. The system of claim 19 wherein the computer executable logic is further configured for execution of:

reading the IO from the journal; and

creating an UNDO for the IO; and

applying the data to the file.

22. The system of claim 21 wherein the computer executable logic is further configured for execution of:

determining that the IO is a command to create a file;

adding the file to a consistency group;

notifying the splitter to split the IO for the file; and

creating the file at the replication site.

23. The system of claim 21 wherein the computer executable logic is further configured for execution of:

determining that the IO is a command to delete a file;

copying the data in the file to an undo journal;

adding a create file to the undo journal; and

deleting the file.