RECOVERY OF A COMPUTER THAT INCLUDES VIRTUAL DISKS

• US 20100049750A1
• Filed: 10/01/2008
• Published: 02/25/2010
• Est. Priority Date: 08/20/2008
• Status: Active Grant

• Current Assignee: Microsoft Technology Licensing LLC (Microsoft Corporation)
• Original Assignee: Microsoft Corporation
• Inventors: Srivastava, Abhinav, Haridas, Dinesh, Wu, Jingbo, Kalach, Ran
• Granted Patent: US 8,150,801 B2
• Time in Patent Office: Days
• US Class Current: N/A
• CPC Class Codes: G06F 11/1435 using file system or storage system metadata
• CPC Class Codes: G06F 11/1458 Management of the backup or restore process
• CPC Class Codes: G06F 11/1469 Backup restoration techniques
• CPC Class Codes: G06F 2201/815 Virtual middleware or OS functionality using virtual machines to implement generic software techniques for error detection or fault masking G06F11/1484

Abstract

Described is the backup and/or restore of virtual disks In general, metadata is backed up for restoring a virtual disk. To restore the disk, a physical disk is created, with the virtual disk the created on a partition of the physical disk. Backup and restore is described for nested virtual disks, including for block level restore. Further described is backing up of critical virtual disks and their containers, and virtual disk backup with respect to basic disks and dynamic volumes.

Claims

1. In a computing environment, a method comprising, restoring a virtual disk, including creating a physical disk, and creating the virtual disk on a partition of the physical disk.

2. The method of claim 1 wherein restoring the virtual disk includes determining that the virtual disk is associated with a first nesting level, and restoring the virtual disk and another virtual disk at a second nesting level in a layered order based on each virtual disk'"'"'s associated level.

3. The method of claim 2 wherein the virtual disk is configured for block level restore, and wherein restoring the virtual disk comprises performing a block level restore at the first nesting level.

4. The method of claim 1 wherein restoring the virtual disk includes surfacing and partitioning the virtual disk in a layered operation.

5. The method of claim 4 wherein the layered operation re-creates any physical disks, re-creates any virtual disks that depend only on physical disks, and re-creates virtual disks that depend on recreated disks.

6. In a computing environment, a method comprising, backing up a virtual disk for subsequent restoration, including maintaining metadata for re-creating the virtual disk.

7. The method of claim 6 wherein the metadata includes dependency information, or wherein the metadata includes level information, or wherein the includes both dependency information and level information.

8. The method of claim 6 further comprising, determining that a volume or disk is critical, and marking the volume or disk as critical.

9. The method of claim 6 further comprising, determining whether a volume inside a mounted virtual disk is critical, and if so, marking the virtual disk and a pack to which it belongs as critical.

10. The method of claim 6 further comprising, determining whether a virtual disk is dependent on a volume or on a virtual disk where its virtual disk files reside, and if so, marking a parent volume of the virtual disk as critical.

11. The method of claim 6 further comprising, determining whether a the parent volume is on a basic disk, and if so, marking a mounted virtual disk as critical, marking a mounted partition as critical, marking a parent partition as critical, and marking a parent disk as critical.

12. The method of claim 6 further comprising, determining whether a parent volume is a dynamic volume, and if so, marking a mounted virtual disk as critical, marking a mounted partition as critical, and marking any dynamic disk that is in a same pack as the disk containing the parent volume as critical.

13. The method of claim 6 further comprising, ensuring that no virtual disk that is marked as critical is dependent on a disk that is excluded at backup.

14. In a computing environment having a computing device, a system comprising, a restore mechanism, including a mechanism that re-creates a physical disk based upon metadata maintained at a backup time of the computing device, and a mechanism that re-creates a virtual disk on the physical disk.

15. The system of claim 14 further comprising a backup mechanism that backs up the metadata at the backup time, including virtual disk metadata, to a medium accessed by the restore mechanism.

16. The system of claim 14 wherein the computing device includes a plurality of virtual disks that are restored by the restore mechanism.

17. The system of claim 15 wherein the computing device includes a boot volume on a virtual disk that is restored by the restore mechanism, in which the virtual disk is associated with a virtual disk file on a physical system partition.

18. The system of claim 15 wherein the computing device includes a physical volume that is restored by the restore mechanism, in which the physical volume contains a virtual disk that backs a boot volume.

19. The system of claim 15 wherein the computing device includes multiple volumes on a single virtual disk that is restored by the restore mechanism, including a volume that is a container for a virtual disk file that contains a plurality of volumes.

20. The system of claim 15 wherein the computing device includes nested virtual disks that are restored by the restore mechanism, including a physical volume contains a boot virtual disk that backs a boot volume and another virtual disk that backs another volume.