Hot recovery of virtual machines

• US 9,760,448 B1
• Filed: 06/30/2014
• Issued: 09/12/2017
• Est. Priority Date: 08/23/2013
• Status: Active Grant

• Current Assignee: MidCap Financial Trust
• Original Assignee: Acronis International GmbH (Acronis AG)
• Inventors: Per, Yuri, Lyadvinsky, Maxim V., Beloussov, Serguei M., Egorov, Dmitry, Borodin, Alexey, Semyonov, Vasily
• Primary Examiner(s): Iqbal, Nadeem
• Application Number:
  US14/320,450
• Time in Patent Office: 1,170 Days
• CPC Class Codes: G06F 11/0757 by exceeding a time limit, i.e. time-out, e.g. watchdogs
• CPC Class Codes: G06F 11/14 Error detection or correction of the data by redundancy in operation G06F11/16 takes precedence
• CPC Class Codes: G06F 11/1435 using file system or storage system metadata
• CPC Class Codes: G06F 11/1448 Management of the data involved in backup or backup restore
• CPC Class Codes: G06F 11/1451 by selection of backup contents
• CPC Class Codes: G06F 11/1461 Backup scheduling policy
• CPC Class Codes: G06F 11/1464 for networked environments
• CPC Class Codes: G06F 11/1469 Backup restoration techniques
• CPC Class Codes: G06F 11/1484 involving virtual machines
• CPC Class Codes: G06F 2201/815 Virtual
• CPC Class Codes: G06F 2201/84 Using snapshots, i.e. a logical point-in-time copy of the data
• CPC Class Codes: G06F 3/0619 in relation to data integrity, e.g. data losses, bit errors
• CPC Class Codes: G06F 3/0647 Migration mechanisms
• CPC Class Codes: G06F 3/0664 at device level, e.g. emulation of a storage device or system
• CPC Class Codes: G06F 3/0673 Single storage device
• CPC Class Codes: G06F 3/0683 Plurality of storage devices
• CPC Class Codes: H04L 67/10 in which an application is distributed across nodes in the network software deployment G06F8/60; multiprogramming arrangements G06F9/46

Abstract

A method, computer program product, and computing system for hot recovery of virtual machines are described. The method may include initiating a recovery process to transfer data, from a backup archive of a virtual machine to be restored, to a virtual disk at the virtual machine host computer. The method may further include booting the virtual machine to be restored. The method may also include intercepting a read request from the virtual machine to the virtual disk at the virtual machine host computer. The method may additionally include determining if the read request from the virtual machine requested data from the virtual disk which has not yet been restored from the backup archive to the virtual disk by the recovery process. Moreover, the method may include, in response to determining that the requested data has not been restored from the backup archive to the virtual disk, returning the requested data.

Claims

1. A method for hot recovery of virtual machines comprising:

initiating, with a virtual machine host computer, a recovery process to transfer data, from a backup archive of a virtual machine to be restored, to a virtual disk at the virtual machine host computer;

booting, from the virtual disk, the virtual machine to be restored;

intercepting a read request from the virtual machine to the virtual disk, wherein the read request is intercepted using a virtual machine communication interface socket;

determining, with the virtual machine host computer, if the read request from the virtual machine requested data from the virtual disk which has not yet been restored from the backup archive to the virtual disk by the recovery process; and

in response to determining that the requested data has not yet been restored from the backup archive to the virtual disk, returning the requested data from the backup archive to the virtual disk.

2. The method of claim 1, further comprising:

intercepting a write request from the virtual machine to the virtual disk, wherein the write request is directed to an area of the virtual disk which has not yet been restored from the backup archive; and

writing data corresponding to the write request to the area of the virtual disk which has not yet been restored from the backup archive.

3. The method of claim 1, further comprising:

determining, with a file system driver, a range of sectors of the virtual disk that needs to be restored from the backup archive to restore the virtual machine in response to the read request, the read request comprising the range of sectors, wherein the range of sectors is determined by comparing checksums of sectors from the backup archive with checksums of sectors of the virtual disk.

4. The method of claim 1, wherein the read request from the virtual machine to the virtual disk is intercepted by a disk drive level filter.

5. The method of claim 3, wherein the file system driver is a virtual small computer system interface filter.

6. The method of claim 1, wherein the requested data is restored from the backup archive to the virtual disk by an agent.

7. A computer program product residing on a non-transitory computer readable storage medium having a plurality of instructions stored thereon, which, when executed by a processor, cause the processor to perform operations for hot recovery of virtual machines, the operations comprising:

initiating, with a virtual machine host computer, a recovery process to transfer data, from a backup archive of a virtual machine to be restored, to a virtual disk at the virtual machine host computer;

booting, from the virtual disk, the virtual machine to be restored;

intercepting a read request from the virtual machine to the virtual disk;

determining, with the virtual machine host computer, if the read request from the virtual machine requested data from the virtual disk which has not yet been restored from the backup archive to the virtual disk by the recovery process; and

in response to determining that the requested data has not yet been restored from the backup archive to the virtual disk, returning the requested data from the backup archive to the virtual disk, wherein the requested data is returned to the virtual disk using a virtual machine communication interface socket.

8. The computer program product of claim 7, wherein the operations further comprise:

intercepting a write request from the virtual machine to the virtual disk, wherein the write request is directed to an area of the virtual disk which has not yet been restored from the backup archive; and

writing data corresponding to the write request to the area of the virtual disk which has not yet been restored from the backup archive.

9. The computer program product of claim 7, wherein the operations further comprise:

determining, with a file system driver, a range of sectors of the virtual disk that needs to be restored from the backup archive to restore the virtual machine in response to the read request, the read request comprising the range of sectors, wherein the range of sectors is determined by comparing checksums of sectors from the backup archive with checksums of sectors of the virtual disk.

10. The computer program product of claim 7, wherein the read request from the virtual machine to the virtual disk is intercepted by a disk drive level filter.

11. The computer program product of claim 10, wherein the file system driver is a virtual small computer system interface filter.

12. The computer program product of claim 7, wherein the requested data is restored from the backup archive to the virtual disk by an agent.

13. A computing system for hot recovery of virtual machines, the computing system comprising one or more processors, wherein the one or more processors are configured to:

initiate, with a virtual machine host computer, a recovery process to transfer data, from a backup archive of a virtual machine to be restored, to a virtual disk at the virtual machine host computer;

boot, from the virtual disk, the virtual machine to be restored;

intercept a read request from the virtual machine to the virtual disk, wherein the read request is intercepted using a virtual machine communication interface socket;

determine, with the virtual machine host computer, if the read request from the virtual machine requested data from the virtual disk which has not yet been restored from the backup archive to the virtual disk by the recovery process; and

in response to determining that the requested data has not yet been restored from the backup archive to the virtual disk, return the requested data from the backup archive to the virtual disk, wherein the requested data is returned to the virtual disk using a virtual machine communication interface socket.

14. The computing system of claim 13, wherein the one or more processors are further configured to:

intercept a write request from the virtual machine to the virtual disk, wherein the write request is directed to an area of the virtual disk which has not yet been restored from the backup archive; and

write data corresponding to the write request to the area of the virtual disk which has not yet been restored from the backup archive.

15. The computing system of claim 13, wherein the one or more processors are further configured to:

determine, with a file system driver, a range of sectors of the virtual disk that needs to be restored from the backup archive to restore the virtual machine in response to the read request, the read request comprising the range of sectors, wherein the range of sectors is determined by comparing checksums of sectors from the backup archive with checksums of sectors of the virtual disk.

16. The computing system of claim 13, wherein the read request from the virtual machine to the virtual disk is intercepted by a disk drive level filter.

17. The computing system of claim 16, wherein the file system driver is a virtual small computer system interface filter.

18. The computing system of claim 13, wherein the requested data is restored from the backup archive to the virtual disk by an agent.

19. A method for recovery of a virtual machine while keeping the virtual machine online, the method comprising:

receiving a selection indicating that a backup archive of a virtual machine is to be restored to a virtual disk at a virtual machine host computer from a storage device, wherein the backup archive is one of a plurality of virtual machine backup archives at the storage device, each representing a point-in-time of the virtual machine to be restored;

in response to receiving the selection, initiating, with an agent that is in communication with the virtual machine host computer, a recovery process to transfer data, from the backup archive of a virtual machine to be restored, to the virtual disk;

upon initiating the recovery process and before the virtual machine has been entirely restored from the backup archive, booting, from the virtual disk, the virtual machine to be restored;

before the virtual machine has been entirely restored from the backup archive, intercepting, with a file system driver running on the virtual machine host computer, a read request from the virtual machine to the virtual disk, wherein the read request is intercepted using a virtual machine communication interface socket;

determining, with the agent that is in communication with the virtual machine host computer, if the read request from the virtual machine requested data from the virtual disk which has not yet been restored from the backup archive to the virtual disk by the recovery process;

in response to determining that the requested data has not yet been restored from the backup archive to the virtual disk, restoring, out of order, the requested data from the backup archive to the virtual disk before the virtual machine has been entirely restored from the backup archive; and

reading, from the virtual disk, the requested data before the virtual machine has been entirely restored from the backup archive.

20. A system comprising:

a virtual machine host computer that hosts a virtual machine;

a virtual disk that stores virtual machine data for running the virtual machine, the virtual disk being accessible to the virtual machine host computer;

a backup archive residing on a storage device, the backup archive including backup virtual machine data for recovery of the virtual machine;

a file system driver that intercepts read requests from the virtual machine to the virtual disk, wherein the read requests are intercepted using a virtual machine communication interface socket; and

an agent, in communication with the file system driver, that restores a portion of the backup virtual machine data from the backup archive to the virtual disk in response to a determination that the virtual machine requested virtual machine data from the virtual disk that is not present on the virtual disk, wherein the portion of the backup virtual machine data corresponds to the requested virtual machine data that is not present on the virtual disk.