US 6,795,966 B1Granted

Mechanism for restoring, porting, replicating and checkpointing computer systems using state extraction

AssigneeVMware, Inc.

InventorsBeng-Hong Lim, Edouard Bugnion, Scott W. Devine

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Abstract

A computer system is interrupted, and its entire state information is extracted as one or more checkpoints at one or more respective points during operation of the system. The checkpoint may be restored into the system at any later time, even multiple times, and it may also even be loaded into one or more other systems; all systems loaded with the same checkpoint will then execute from the same checkpointed state. The state extraction mechanism is preferably a virtual machine monitor, on which one or more virtual machines are installed, each virtual machine constituting an encapsulated, virtualized computer system whose states can be checkpointed under control of the virtual machine monitor. Checkpoints may be stored on a portable memory device or transmitted as a batch or dynamically over a network so that even virtual machines installed at different sites may execute from the same state.

Claims21

Dependent claims

A computer system comprising:

a hardware processor;
physical system storage;
a virtual machine monitor functionally connected to the hardware processor and physical system storage;
a virtual machine functionally connected to the virtual machine monitor and including:
a virtual processor that has a plurality of registers and executes a sequence of virtual processor instructions, virtual processor instructions being conveyed by the virtual machine monitor to the hardware processor, physical execution of the virtual processor instructions being carried out by the hardware processor;
a virtual memory;
a virtual operating system;
at least one virtual peripheral device having a plurality of peripheral settings and peripheral device data;
at least one application program loaded in the virtual machine and executing on the virtual machine under the control of the virtual operating system;
in which:
at the completion of execution of each processor instruction by the virtual processor, the virtual machine having a total state that includes state information of the virtual processor, of the virtual memory, of the virtual operating system, of each application program, and of each virtual peripheral device;
the virtual machine monitor including a checkpointing mechanism:
for interrupting the virtual processor;
for sensing a checkpoint request for the virtual machine;
for generating at least one checkpoint, each checkpoint comprising a list of the total state of the virtual machine corresponding to the respective checkpoint request, at the completion of execution of a respective virtual processor instructions;
for storing each generated checkpoint;
for sensing a state restoration request corresponding to one of the checkpoints;
and
upon sensing the state restoration request, for restoring into the virtual machine the total state corresponding to the checkpoint that in turn corresponds to the state restoration request, the virtual machine thereby resuming execution from the restored total state, that is, of the sequence of virtual processor instructions following the virtual processor instruction after whose completion the checkpoint was generated, identically as it would have if the virtual processor had not been interrupted;
the physical system storage includes a checkpoint storage portion accessible only by the virtual machine monitor;
and
each generated checkpoint is stored in the checkpoint storage portion, stored checkpoints thereby remaining unchanged by other access to the physical system storage, the total state of the virtual machine excluding the contents of the corresponding checkpoint storage portion.

19 more elements

A computer system comprising:

a hardware processor;
physical system storage;
a virtual machine monitor functionally connected to the hardware processor and physical system storage;
a virtual machine functionally connected to the virtual machine monitor and including:
a virtual processor that has a plurality of registers and executes a sequence of virtual processor instructions, virtual processor instructions being conveyed by the virtual machine monitor to the hardware processor, physical execution of the virtual processor instructions being carried out by the hardware processor;
a virtual memory;
a virtual operating system;
at least one application program executing on the virtual machine;
in which:
at the completion of execution of each processor instruction by the virtual processor, the virtual machine having a total state that includes state information of the virtual processor, of the virtual memory, of the virtual operating system, and of each application program;
the virtual machine monitor including a checkpointing mechanism:
for interrupting the virtual processor;
for sensing a checkpoint request for the virtual machine;
and
for generating at least one checkpoint, each checkpoint comprising a list of the total state of the virtual machine corresponding to the respective checkpoint request, at the completion of execution of a respective virtual processor instruction;
in which;
one of the virtual machines is a source virtual machine, for which at least one checkpoint is generated;
the checkpointing mechanism is further provided for loading into at least one secondary virtual machine, which is different from the source virtual machine, the total state of the source virtual machine corresponding to one of the generated checkpoints.

15 more elements

In a computer system that includes:

a hardware platform, which in turn includes a hardware processor and system storage;
a plurality of virtual machines monitor functionally connected to the hardware platform;
at least one virtual machine functionally connected to a virtual machine monitor and communicating with the hardware platform via the virtual machine monitor, each virtual machine having a virtual processor, which executes a series of virtual processor instructions, and a virtual memory;
and
a method comprising the following steps:
in the virtual machine monitor, sensing at least one checkpoint request relating to a source virtual machine included among the plurality of virtual machines;
upon sensing each checkpoint request, interrupting the virtual processor of the source virtual machine and generating a corresponding checkpoint, which comprises a list of a total state of the source virtual machine, including state information of the source virtual machine's virtual processor, virtual memory, and of any application running on the source virtual machine;
loading into at least one secondary virtual machine, selected from among the plurality of virtual machines, a checkpoint corresponding to the total state of a different one of the virtual machines, that is, a source virtual machine;
resuming unmodified execution of the source virtual machine after the step of generating each checkpoint, as well as starting execution of each secondary virtual machine from the checkpointed state of the source virtual machine, whereby the state of the source virtual machine is replicated in the secondary virtual machines.

6 more elements

In a computer system that includes:

a hardware platform, which in turn includes a hardware processor and system storage;
a virtual machine monitor functionally connected to the hardware platform;
at least one virtual machine functionally connected to the virtual machine monitor and communicating with the hardware platform via the virtual machine monitor, the virtual machine having a virtual processor, which executes a series of virtual processor instructions, and a virtual memory;
and
at least one application program running on at least one of the virtual machines;
a method comprising the following steps:
in the virtual machine monitor, sensing at least one checkpoint request;
upon sensing each checkpoint request, interrupting the virtual processor of the virtual machine and generating a corresponding checkpoint, which comprises a list of a total state of the virtual machine, including state information of the virtual processor, the virtual memory, and of any application running on the virtual machine
in which the steps of sensing each checkpoint request and generating a corresponding checkpoint includes the following sub-steps:
generating an initial checkpoint including the total state of the virtual machine;
and
for at least one subsequent checkpoint after the initial checkpoint, generating the subsequent checkpoint as a list of state changes relative to an immediately preceding generated checkpoint as well as link information to the immediately preceding generated checkpoint.

9 more elements

In a computer system that includes:

a hardware platform, which in turn includes a hardware processor and system storage;
at least one peripheral system hardware device;
a virtual machine monitor functionally connected to the hardware platform;
a virtual machine functionally connected to the virtual machine monitor and communicating with the hardware platform via the virtual machine monitor, each virtual machine having a virtual processor, which executes a series of virtual processor instructions, and a virtual memory;
and
at least one application program running in the virtual machine;
a method comprising the following steps:
for each peripheral system hardware device, installing in the virtual machine monitor a respective device emulation module corresponding to a predetermined emulation of a representative, virtualized hardware device corresponding to the peripheral system hardware device;
in the virtual machine monitor, converting device control signals and data from the virtual machine issued in a format of the respective representative virtualized hardware device into corresponding signals and data into a format of the corresponding peripheral system hardware device, and vice versa;
the virtual machine thereby being independent of an underlying hardware platform, the total state of the virtual machine thereby being exportable to any other, secondary virtual machine;
in the virtual machine monitor, sensing at least one checkpoint request relating to the virtual machine, which is a source virtual machine;
upon sensing each checkpoint request, interrupting the virtual processor of the source virtual machine and generating a corresponding checkpoint, which comprises a list of a total state of the source virtual machine, including state information of the virtual processor, the virtual memory, and of any application running on the source virtual machine;
and
loading the checkpoint of the state of the source virtual machine into at least one other, secondary virtual machine, the secondary virtual machine thereby being able to proceed from the checkpoint independently of all other virtual machines.

11 more elements

Dependencies are inferred from the claim text.

Facts

Application: 09/497,978Filed 4 Feb 2000 · continuation in part
Priority: 15 Feb 1998
Granted: 21 Sep 2004
Term ends: Not estimatedThe source records don’t support an estimate.

Classification7 codes

G06F 11/1438
At system level: restarting or rejuvenating
G06F 9/45558
Hypervisors; Virtual machine monitors: hypervisor-specific management and integration aspects
G06F 11/203
Failover techniques: using migration
G06F 2009/45562
Hypervisor-specific management and integration aspects: creating, deleting, cloning virtual machine instances

Family

Application60/085,685Us provisional application · filed 15 Feb 1998
Application09/151,175Parent of this continuation-in-part · filed 10 Sep 1998
Application60/118,862Us provisional application · filed 5 Feb 1999
US 6,496,847 B1Parent of this continuation-in-part · filed 17 Dec 2002
US 6,795,966 B1This patent

From the US filing history. Foreign family members aren’t listed.