Background migration of virtual storage

Patent metadata

Field	Value
Publication number	US-2016004467-A1
Application number	US-201514789860-A
Country	US
Kind code	A1
Filing date	Jul 1, 2015
Priority date	Feb 8, 2010
Publication date	Jan 7, 2016
Grant date	—

Abstract

Described is a technology by which a virtual hard disk is migrated from a source storage location to a target storage location without needing any shared physical storage, in which a machine may continue to use the virtual hard disk during migration. This facilitates use the virtual hard disk in conjunction with live-migrating a virtual machine. Virtual hard disk migration may occur fully before or after the virtual machine is migrated to the target host, or partially before and partially after virtual machine migration. Background copying, sending of write-through data, and/or servicing read requests may be used in the migration. Also described is throttling data writes and/or data communication to manage the migration of the virtual hard disk.

First claim

1 - 20 . (canceled)

21 . In a computing environment, a method performed on at least one processor, the method comprising:
migrating a virtual machine and a storage component of the virtual machine from a source location to a target location while the virtual machine is running on one or more of the source location and the target location; during the migration, receiving a request associated with data in the storage component of the virtual machine; on condition that the request is associated with data that has been migrated to the target location, accessing the target location to service the request using the data that has been migrated to the target location; and on condition that the request is associated with data that has not been migrated to the target location, accessing the source location or another location accessible to the target location to service the request using the data that has not been migrated to the target location.

22 . The method of claim 21 , further comprising:
background copying the data in the storage component of the virtual machine from the source location to the target location at a first priority; and sending written data corresponding to newly-written writes directed towards the source location to the target location at a second priority that is at least as high as the first priority, the request being a write request.

23 . The method of claim 22 , further comprising throttling the migration of at least a portion of the storage component of the virtual machine to control a rate of transfer of the newly-written writes.

24 . The method of claim 22 , further comprising throttling the background copying from the source location to the target location to utilize less than a maximum transfer rate of a network over which the background copy is occurring.

25 . The method of claim 21 , further comprising background copying the data located in the storage component of the virtual machine from the source location to the target location at a first priority, wherein accessing the source location or the another location accessible to the target location comprises servicing the request at a second priority that is at least as high as the first priority, the request being a read request.

26 . The method of claim 25 , further comprising throttling a sending of read data corresponding to the read request to control a rate of transfer via a network over which the read request is occurring.

27 . The method of claim 21 , further comprising controlling migration of the virtual machine, wherein the virtual machine is configured to migrate before, during, or after the migration of the data in the storage component of the virtual machine.

28 . The method of claim 21 , further comprising obtaining one or more descriptions of data regions from at least one of the source location or the another location.

29 . One or more computer storage devices having computer-executable instructions that are executable by a computer to cause the computer to perform operations comprising:
copying virtual hard disk data from a source location to a target location while a virtual machine is running on one or more of the source location and the target location; and receiving a read request for at least a portion of the virtual hard disk data while the virtual hard disk data is being copied from the source location to the target location; on condition that the portion of the virtual hard disk data corresponding to the read request has been copied to the target location, using the portion of the virtual hard disk data that has already been copied to the target location; and on condition that the portion of the virtual hard disk data corresponding to the read request has not been migrated to the target location, obtaining the portion of the virtual hard disk data from one or more of the source location and another location accessible to the target location.

30 . The one or more computer storage devices of claim 29 having further computer-executable instructions that are executable by the computer to cause the computer to perform operations comprising sending newly-written writes directed towards the source location as written data to the target location, wherein the sending of the newly-written writes occurs at a priority that is at least as high as a priority of the copying.

31 . The one or more computer storage devices of claim 29 having further computer-executable instructions that are executable by the computer to cause the computer to perform operations comprising:
sending newly-written writes directed towards the source location as written data to the target location over a network; and
throttling to control a rate of transfer of the newly-written writes.

32 . The one or more computer storage devices of claim 29 having further computer-executable instructions that are executable by the computer to cause the computer to perform operations comprising reading at least some data from a base layer of the virtual hard disk that is accessible by the target location into the target location without sending that data from the source location.

33 . The one or more computer storage devices of claim 29 having further computer-executable instructions that are executable by the computer to cause the computer to perform operations comprising obtaining descriptions of data regions that the target location needs from at least one of the source location or the another location.

34 . The one or more computer storage devices of claim 29 having further computer-executable instructions that are executable by the computer to cause the computer to perform operations comprising tracking dirty regions corresponding to writes that the target location needs to obtain from the source location.

35 . In a computing environment, a system comprising:
a memory storing data associated with one or more virtual machines and one or more virtual hard disks; and one or more agents configured to:
copy virtual hard disk data from a source virtual machine host to a target virtual machine host while a virtual machine is running on one or more of the source virtual machine host and the target virtual machine host;
receive a read request for at least a portion of the virtual hard disk data while the virtual hard disk data is being copied from the source location to the target location;
on condition that the portion of the virtual hard disk data corresponding to the read request has been copied to the target location, use the portion of the virtual hard disk data that has already been copied to the target location; and
on condition that the portion of the virtual hard disk data corresponding to the read request has not been migrated to the target location, obtain the portion of the virtual hard disk data from one or more of the source location and another location accessible to the target location.

36 . The system of claim 35 , wherein the one or more agents are configured to send newly-written writes directed towards the source virtual machine host as written data to the target virtual machine host, wherein the sending of the newly-written writes occurs at a priority that is at least as high as a priority of the copying.

37 . The system of claim 35 , wherein the one or more agents are configured to:
send newly-written writes directed towards the source virtual machine host as written data to the target virtual machine host over a network; and throttle to control a rate of transfer of the newly-written writes.

38 . The system of claim 35 , wherein the

Assignees

• Microsoft Technology Licensing Llc

Inventors

• Green Dustin L
• Oshins Jacob K
• Reuther Lars

Classifications

• G06F3/0659

  Command handling arrangements, e.g. command buffers, queues, command scheduling · CPC title

• G06F11/2066

  Optimisation of the communication load · CPC title

• G06F3/065

  Replication mechanisms · CPC title

• G06F3/0619 Primary

  in relation to data integrity, e.g. data losses, bit errors · CPC title

• G06F3/0647

  Migration mechanisms · CPC title