UPGRADABLE BASE IMAGE OF VIRTUAL MACHINE

• US 20180011871A1
• Filed: 07/08/2016
• Published: 01/11/2018
• Est. Priority Date: 07/08/2016
• Status: Active Grant

• Current Assignee: International Business Machines Corporation
• Original Assignee: International Business Machines Corporation
• Inventors: KROLL, Marco H., POHL, Thomas, TROESTER, Martin
• Granted Patent: US 10,318,486 B2
• Time in Patent Office: Days
• CPC Class Codes: G06F 16/1748 De-duplication implemented within the file system, e.g. based on file segments de-duplication techniques in storage systems for the management of data blocks G06F3/0641
• CPC Class Codes: G06F 16/188 Virtual file systems
• CPC Class Codes: G06F 2009/45562 Creating, deleting, cloning virtual machine instances
• CPC Class Codes: G06F 2009/45583 Memory management, e.g. access or allocation
• CPC Class Codes: G06F 2009/45587 Isolation or security of virtual machine instances
• CPC Class Codes: G06F 8/65 Updates security arrangements therefor G06F21/57
• CPC Class Codes: G06F 9/45558 Hypervisor-specific management and integration aspects

Abstract

A method for de-duplicating updates in virtual machines (VMs) is provided that may be executed on a host computer using a hypervisor. Client VMs are derived from a base image, and the method includes: creating a temporary virtual machine, updating the temporary virtual machine, identifying modified blocks of the updated temporary virtual machine, and identifying files associated with the modified blocks. Moreover, the method includes determining block identifiers of matching files of a VM corresponding to identified files of the updated temporary VM, moving block content of blocks relating to the determined block identifiers from its initial location to a free location within the client VM if the block content and the matching files are not identical in the client virtual machine and the temporary VM, and de-duplicating content within the client VM, generating a complete bootable image, and replacing the base image by the temporary VM.

Claims

1. A computer-implemented method for de-duplication of updates in virtual machines being executed on a host computer system using a hypervisor, wherein a client virtual machine is derived from a base image, the method comprising:

creating a temporary virtual machine based on the base image;

updating the temporary virtual machine with the updates;

identifying modified blocks in a temporary image of the temporary machine when compared to the base image;

identifying files associated with the modified blocks in the updated temporary image;

determining block identifiers of matching files in the temporary image of the temporary virtual machine corresponding to identified files in the image of the updated temporary virtual machine;

moving block content of blocks relating to the determined block identifiers from its initial location to a free location within the client virtual machine if the block content and the matching files are not identical in the image of the client virtual machine and the temporary image of the temporary virtual machine;

de-duplicating content within the client virtual machine by replacing block content at an initial location of the matching files in the image of the client virtual machine with pointers to corresponding blocks in the temporary image of the temporary virtual machine;

generating a complete bootable image of the temporary virtual machine by using blocks of the base image which have not been updated; and

replacing the base image by the image of the temporary virtual machine making the temporary virtual machine a new base image.

2. The method according to claim 1, wherein the creating a temporary virtual machine is performed by a copy-on-write technique.

3. The method according to claim 2, wherein the identifying modified blocks of the updated temporary image comprises using block identifiers determined during performing the copy-on-write technique.

4. The method according to claim 1, wherein the updating the temporary virtual machine with the updates comprises booting the temporary virtual machine before the updating.

5. The method according to claim 1, wherein the moving block content comprises replacing content of the matching files of the image of the client virtual machine with reference to the matching file in the image of the temporary virtual machine.

6. The method according to claim 1, wherein moving block content comprises comparing content of each identified file of the image of the updated temporary virtual machine with image of the temporary virtual machine resulting in block identifiers of the matching files.

7. The method according to claim 1, wherein the replacing the base image by the image of the temporary virtual machine comprises deleting the base image and replacing all pointers to the base image by pointers to the new base image.

8. The method according to claim 1, wherein the de-duplicating content within the image of client virtual machine comprises ensuring that an original sequence of blocks per matching file stays unchanged if compared to an original file.

9. A de-duplication system for updates in virtual machines being executed on a host computer system using a hypervisor, wherein a client virtual machine is derived from a base image stored on a host computer system, the de-duplication system comprising:

a memory; and

a processor communicatively coupled to the memory, wherein the de-duplication system performs a method comprising;

creating a temporary virtual machine based on the base image;

updating the temporary virtual machine with the updates;

identifying modified blocks in a temporary image of the temporary machine when compared to the base image;

identifying files associated with the modified blocks in the updated temporary image;

determining block identifiers of matching files in the temporary image of the temporary virtual machine corresponding to identified files in the image of the updated temporary virtual machine;

moving block content of blocks relating to the determined block identifiers from its initial location to a free location within the client virtual machine if the block content and the matching files are not identical in the image of the client virtual machine and the temporary image of the temporary virtual machine;

de-duplicating content within the client virtual machine by replacing block content at an initial location of the matching files in the image of the client virtual machine with pointers to corresponding blocks in the temporary image of the temporary virtual machine;

generating a complete bootable image of the temporary virtual machine by using blocks of the base image which have not been updated; and

replacing the base image by the image of the temporary virtual machine making the temporary virtual machine a new base image.

10. The de-duplication system according to claim 9, wherein the creating a temporary virtual machine is performed by a copy-on-write technique.

11. The de-duplication system according to claim 10, wherein the identifying modified blocks of the updated temporary image comprises using block identifiers determined during performing the copy-on-write technique.

12. The de-duplication system according to claim 9, wherein the updating the temporary virtual machine with the updates comprises booting the temporary virtual machine before the updating.

13. The de-duplication system according to claim 9, wherein the moving block content comprises replacing content of the matching files of the image of client virtual machine with reference to the matching file in the image of temporary virtual machine.

14. The de-duplication system according to claim 9, wherein the moving block content comprises comparing content of each identified file of the image of the updated temporary virtual machine with the image of the temporary virtual machine resulting in block identifiers of the matching files.

15. The de-duplication system according to claim 9, wherein the replacing the base image by the image of the temporary virtual machine comprises deleting the base image and replacing all pointers to the base image by pointers to the new base image.

16. The de-duplication system according to claim 9, wherein the de-duplicating content within the image of the client virtual machine comprises ensuring that an original sequence of blocks per matching file stays unchanged if compared to an original file.

17. A computer program product for de-duplication of common updates in virtual machines being executed on a host computer system using a hypervisor, wherein a plurality of virtual machines are derived from a base image, the computer program product comprising:

a computer readable storage medium having program instructions embodied therewith, the program instructions being executable by a computer system to cause the computer system to perform a method comprising;

creating a temporary virtual machine based on the base image;

updating the temporary virtual machine with the updates;

identifying modified blocks in a temporary image of the temporary machine when compared to the base image;

identifying files associated with the modified blocks in the updated temporary image;

determining block identifiers of matching files in the temporary image of the temporary virtual machine corresponding to identified files in the image of the updated temporary virtual machine;

moving block content of blocks relating to the determined block identifiers from its initial location to a free location within the client virtual machine if the block content and the matching files are not identical in the image of the client virtual machine and the temporary image of the temporary virtual machine;

de-duplicating content within the client virtual machine by replacing block content at an initial location of the matching files in the image of the client virtual machine with pointers to corresponding blocks in the temporary image of the temporary virtual machine;

generating a complete bootable image of the temporary virtual machine by using blocks of the base image which have not been updated; and

replacing the base image by the image of the temporary virtual machine making the temporary virtual machine a new base image.