Virtual machine migration between servers

• US 20070220121A1
• Filed: 03/18/2006
• Published: 09/20/2007
• Est. Priority Date: 03/18/2006
• Status: Active Grant

• Current Assignee: Taiwan Semiconductor Manufacturing Company Limited
• Original Assignee: International Business Machines Corporation
• Inventors: Suwarna, Ignatia
• Granted Patent: US 8,042,108 B2
• Time in Patent Office: Days
• US Class Current: 709/220
• CPC Class Codes: G06F 9/4856 resumption being on a different machine, e.g. task migration, virtual machine migration G06F9/5088 takes precedence
• CPC Class Codes: G06F 9/5077 Logical partitioning of resources; Management or configuration of virtualized resources specific details on emulation or internal functioning of virtual machines G06F9/455
• CPC Class Codes: H04L 67/1097 for distributed storage of data in networks, e.g. transport arrangements for network file system [NFS], storage area networks [SAN] or network attached storage [NAS]

Abstract

A virtual machine is migrated between two servers. A method, at the first server, dismounts a volume on which all the files relating to the virtual machine are stored, and which was previously mounted at the first server. The method, at the second server, mounts the volume on which all the files relating to the virtual machine are stored, so that the second server can host the virtual machine. In this way, the virtual machine can be migrated without having to copy all the files from the first server to the second server. The files relating to the virtual machine are stored on a storage-area network (SAN).

Claims

1. A method for migrating a virtual machine from a first server to a second server, comprising:

at the first server,

dismounting a volume on which all files relating to the virtual machine are stored and which was previously mounted at the first server; and

,

at the second server,

mounting the volume on which all the files relating to the virtual machine are stored,

such that the virtual machine is migrated from the first server to the second server without copying all the files relating to the virtual machine from the first server to the second server.

2. The method of claim 1, further comprising, at the first server, prior to dismounting the volume:

turning off the virtual machine; and

,

unregistering the virtual machine at the first server.

3. The method of claim 1, further comprising, at the first server, prior to dismounting the volume, flushing any file buffers of the first server that have buffered any of the files relating to the virtual machine.

4. The method of claim 1, further comprising, at the second server, after mounting the volume:

registering the virtual machine at the second server; and

,

turning on the virtual machine.

5. The method of claim 1, further comprising, at the first server,

prior to dismounting the volume, delineating a server-neutral and substantially universal identification of the volume;

and,

transmitting the server-neutral and substantially universal identification of the volume to the second server.

6. The method of claim 5, further comprising, at the second server, prior to mounting the volume, receiving the server-neutral and substantially universal identification of the volume from the first server, wherein the identification of the volume is used by the second server to mount the volume thereat.

7. The method of claim 5, wherein delineating the server-neutral and substantially universal identification of the volume comprises:

determining a number of partitions over which the volume extends; and

,

for each partition over which the volume extends,

determining a starting offset, extension size, and disk signature of the partition,

wherein the identification of the volume includes the starting offset, extension size, and disk signature for each partition over which the volume extends.

8. The method of claim 1, wherein the files relating to the virtual machine are physically located on a storage-area network (SAN), are visible to both the first server and the second server, but initially accessible just to the first server.

9. A system comprising:

a storage-area network (SAN) physically storing all files relating to a virtual machine over one or more partitions of hard disks of the SAN;

a first server at which a volume logically storing all the files relating to the virtual machine is mounted and at which the virtual machine is hosted;

a second server to which the virtual machine is to be migrated;

a first agent running on the first server to dismount the volume; and

,

a second agent running on the second server to mount the volume at the second server,

wherein the virtual machine is migrated from the first server to the second server without copying all the files relating to the virtual machine from the first server to the second server.

10. The system of claim 9, wherein the first agent is further to turn off the virtual machine and unregister the virtual machine from the first server prior to dismounting the volume.

11. The system of claim 9, wherein the second agent is further to register the virtual machine at the second server, such that the virtual machine is hosted at the second server, and to turn on the virtual machine, after mounting the volume.

12. The system of claim 9, further comprising a third server hosting a virtual machine manager,

wherein the first agent is further to delineate a server-neutral and substantially universal identification of the volume prior to dismounting the volume, and to transmit the identification of the volume to the second agent via the virtual machine manager,

and wherein the second agent is to receive the identification of the volume from the first agent via the virtual machine manager, and is to use the identification of the volume to mount the volume thereat.

13. The system of claim 12, wherein the identification of the volume comprises, for each partition over which the volume extends, a starting offset, extension size, and disk signature of the partition.

14. An article of manufacture comprising:

a tangible computer-readable medium; and

,

means in the medium for migrating a virtual machine from a first server to a second server without having to copy all files relating to the virtual machine from the first server to the second server,

wherein a part of the means at the first server dismounts a volume on which all the files relating to the virtual machine are stored,

and wherein a part of the means at the second server of the means mounts the volume on which all the files relating to the virtual machine are stored.

15. The article of manufacture of claim 14, wherein the part of the means at the first server turns off the virtual machine and unregisters the virtual machine from the first server prior to dismounting the volume.

16. The article of manufacture of claim 14, wherein the part of the means at the second server registers the virtual machine at the second server and turns on the virtual machine after mounting the volume.

17. The article of manufacture of claim 14, wherein the part of the means at the first server is to delineate a server-neutral and substantially universal identification of the volume prior to dismounting the volume, and to transmit the identification of the volume to the part of the means at the second server.

18. The article of manufacture of claim 17, wherein the part of the means at the second server is to receive the identification of the volume, and to use the identification of the volume to mount the volume thereat.

19. The article of manufacture of claim 17, wherein the identification of the volume comprises, for each of one or more partitions over which the volume extends, starting offset, extension size, and disk signature of the partition.

20. The article of manufacture of claim 14, wherein the files relating to the virtual machine are physically located on a storage-area network (SAN), are visible to both the first server and the second server, but initially accessible just to the first server.