Data access during data recovery

Patent metadata

Field	Value
Publication number	US-9697086-B2
Application number	US-82821310-A
Country	US
Kind code	B2
Filing date	Jun 30, 2010
Priority date	Jun 30, 2010
Publication date	Jul 4, 2017
Grant date	Jul 4, 2017

Abstract

A method, article of manufacture, and apparatus for accessing data during data recovery. In some embodiments, this includes sending an I/O request from an application to an object, wherein the object is being recovered, establishing an I/O intercept, intercepting the application's I/O request with the I/O intercept, and redirecting the I/O request based on the status of the object's sub-objects.

First claim

What is claimed is:

1. A method for accessing data during data recovery, comprising:
intercepting, at an I/O intercept, an application's I/O request to access an object that is being recovered as part of a data recovery operation currently being performed on a storage device, wherein the object includes one or more sub-objects;
in response to intercepting the I/O request, determining a recovery status for a first sub-object in relation to the data recovery operation, wherein the determining the recovery status of the first sub-object includes determining whether the first sub-object is available via local I/O, remote I/O, or recovery on access;
determining, based at least in part on the determined recovery status of the first sub-object, an access method for the application to access the object, wherein determining the access method includes determining whether to change a priority of the first sub-object, and determining whether the first sub-object is to be accessed via local I/O, remote I/O, or recovery on access based at least in part on the recovery status for the first sub-object, and wherein the I/O intercept is configured to apply the determined access method and transparently redirect the application's I/O request, wherein the determining of the access method is performed in connection with the recovery operation currently being performed on the storage device;
in the event that the first sub-object is determined to be available via local I/O and the application has successfully performed I/O on the local copy of the first sub-object, abolishing the I/O intercept with regard to the local copy of the first sub-object after the application has successfully performed I/O on the local copy of the first sub-object, wherein in the event that the I/O intercept is abolished, the application directly accesses the local copy of the first sub-object; and
in the event that the first sub-object is determined to be available via local I/O and the application has not performed I/O on the local copy of the first sub-object, rerouting, by the I/O intercept, the application's I/O request to access the object to a recovery service that manages recovery of the object.

2. The method as recited in claim 1 , wherein in the event that the first sub-object is determined to be available via local I/O, the access method for the application to access the object includes redirecting the I/O request to a local copy of the first sub-object.

3. The method as recited in claim 1 , wherein in the event that the first sub-object is determined to be available via remote I/O, the access method for the application to access the object includes redirecting the I/O request to a remote copy of the first sub-object.

4. The method as recited in claim 3 , wherein the first sub-object is available via remote access and the I/O request is redirected to a remote copy of the first sub-object based at least in part on a pinned status of at least the first sub-object, and wherein pinning at least the first sub-object restricts access to the first sub-object to remote I/O.

5. The method as recited in claim 3 , further comprising spinning up at least the first sub-object on a system and establishing a connection between the application and the spun-up first sub-object.

6. The method as recited in claim 5 , wherein the system comprises a virtual machine mounted on top of a physical machine that is connected by a comparatively high bandwidth connection to a storage container storing the first sub-object.

7. The method as recited in claim 1 , wherein in the event that the first sub-object is determined to be available via recovery on access, the access method for the application to access the object includes holding the I/O request until the first sub-object has been recovered.

8. The method as recited in claim 1 , wherein the object is segmented into the one or more sub-objects based at least in part on one or more of the following: a predefined segment interval, an access pattern associated with the object, metadata, one or more policies, and one or more user commands.

9. The method as recited in claim 1 , wherein each of at least a subset of the one or more sub-objects is assigned a recovery priority based at least in part on one or more of the following: an access pattern associated with the object, metadata, one or more polices, and one or more user commands.

10. The method of claim 9 , wherein the recovery priority corresponding to at least one of the one or more sub-objects is dynamically changed during the data recovery operation.

11. The method of claim 10 , wherein the recovery priority corresponding to the at least one of the one or more sub-objects is dynamically changed during the data recovery operation based on one or more access requests for the at least one of the one or more sub-objects.

12. The method as recited in claim 1 , further comprising:
in the event that the first sub-object is determined to be available via remote I/O, the access method includes accessing the first sub-object is to be accessed via remote I/O, and the application has successfully performed I/O on the remote copy of the first sub-object, preserving the I/O intercept with regard to the remote copy of the first sub-object.

13. The method as recited in claim 1 , wherein each of at least a subset of the one or more sub-objects is assigned a recovery priority, wherein the recovery priority is stored in metadata or a header associated with the subset of the one or more sub-objects.

14. The method of claim 13 , wherein the recovery priority for at least one of the one or more sub-objects is updated during the recovery operation based at least in part on an access request for accessing the at least one of the one or more sub-objects.

15. A system for accessing data during data recovery, comprising a storage device and a processor configured to:
intercept, at an I/O intercept, an application's I/O request to access an object that is being recovered as part of a data recovery operation currently being performed on a storage device, wherein the object includes one or more sub-objects, and wherein the I/O intercept is transparent to the application;
in response to intercepting the I/O request, determine a recovery status for a first sub-object in relation to the data recovery operation, wherein the determining the recovery status of the first sub-object includes determining whether the first sub-object is available via local I/O, remote I/O, or recovery on access;
determine, based at least in part on the determined recovery status of the first sub-object, an access method for the application to access the object, wherein determining the access method includes determining whether to change a priority of the first sub-object, and determining whether the first sub-object is to be accessed via local I/O, remote I/O, or recovery on access based at least in part on the recovery status for the first sub-object, and wherein the I/O intercept is configured to apply the determined access method and transparently redirect the application's I/O request, wherein determining the access method is performed in connection with the recovery operation currently being performed on the storage device;
in the event that the first sub-object is determined to be available via local I/O and the application has successfully performed I/O on the local copy of the first sub-object, abolish the I/O intercept with regard to the local copy of the first sub-object after the application has successfully performed I/O on the local copy of the first sub-object, wherein in the event that the I/O intercept is abolished, the appl

Assignees

• Dutch Michael John
• Claudatos Christopher Hercules
• Rao Mandavilli Navneeth
• Emc Ip Holding Co Llc

Inventors

• Dutch Michael John
• Claudatos Christopher Hercules
• Rao Mandavilli Navneeth

Classifications

• G06F11/1466

  to make the backup process non-disruptive · CPC title

• G06F11/1469

  Backup restoration techniques · CPC title

• G06F11/1448 Primary

  Management of the data involved in backup or backup restore · CPC title

• G06F13/26

  with priority control · CPC title

• G06F13/385

  for adaptation of a particular data processing system to different peripheral devices · CPC title