Virtual machine migration
AssigneeVMware, Inc.
InventorMichael Nelson
Life of this patent
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Abstract
A source virtual machine (VM) hosted on a source server is migrated to a destination VM on a destination server without first powering down the source VM. After optional pre-copying of the source VM's memory to the destination VM, the source VM is suspended and its non-memory state is transferred to the destination VM; the destination VM is then resumed from the transferred state. The source VM memory is either paged into the destination VM on demand, or is transferred asynchronously by pre-copying and write-protecting the source VM memory, and then later transferring only the modified pages after the destination VM is resumed. The source and destination servers preferably share common storage, in which the source VM's virtual disk is stored; this avoids the need to transfer the virtual disk contents.
Claims27
A computer program embodied in a computer-readable storage medium, the computer program implementing a method for migrating a source virtual machine (VM) installed on a source computer to a destination computer, the method comprising:
- transferring source VM memory to a destination VM on the destination computer while the source VM is executing on the source computer;
- suspending execution of the source VM;
- transferring non-memory source VM state information to the destination VM, thereby enabling execution of the destination VM from the transferred non-memory source VM state;
- and
- retransferring to the destination VM any units of the source VM memory that have been modified since the source VM memory was previously transferred from the source VM to the destination VM.
A virtual computer system comprising:
- a source virtual machine (VM) executing on a source computer;
- a destination VM configured on a destination computer;
- and
- computer software executing on the source and destination computers, the computer software implementing a method for migrating the source VM to the destination computer, the method comprising:
- transferring source VM memory to the destination VM while the source VM is executing on the source computer;
- suspending execution of the source VM;
- transferring non-memory source VM state information to the destination VM, thereby enabling execution the destination VM from the transferred non-memory source VM state;
- and
- retransferring to the destination VM units of the source VM memory that have been modified since they were previously transferred from the source VM to the destination VM.
Dependencies are inferred from the claim text.