Rapid virtual machine suspend and resume

• US 9,575,688 B2
• Filed: 02/25/2013
• Issued: 02/21/2017
• Est. Priority Date: 12/14/2012
• Status: Active Grant

• Current Assignee: Vmware LLC (Broadcom, Inc.)
• Original Assignee: VMware, Inc. (Broadcom, Inc.)
• Inventors: Thirumal, Thiruvengada Govindan, Goyal, Neeraj, Beveridge, Daniel James, Madnani, Kiran
• Primary Examiner(s): Bragdon, Reginald
• Assistant Examiner(s): Faye-Joyner, Hannah A
• Application Number:
  US13/775,700
• Publication Number:
  US 20140173196A1
• Time in Patent Office: 1,457 Days
• US Class Current: 1/1
• CPC Class Codes: G06F 11/14 Error detection or correction of the data by redundancy in operation G06F11/16 takes precedence
• CPC Class Codes: G06F 11/1438 Restarting or rejuvenating
• CPC Class Codes: G06F 12/0813 with a network or matrix configuration
• CPC Class Codes: G06F 12/084 with a shared cache
• CPC Class Codes: G06F 12/0868 Data transfer between cache memory and other subsystems, e.g. storage devices or host systems
• CPC Class Codes: G06F 12/126 with special data handling, e.g. priority of data or instructions, handling errors or pinning
• CPC Class Codes: G06F 2009/45575 Starting, stopping, suspending or resuming virtual machine instances
• CPC Class Codes: G06F 2201/815 Virtual middleware or OS functionality using virtual machines to implement generic software techniques for error detection or fault masking G06F11/1484
• CPC Class Codes: G06F 2212/152 Virtualized environment, e.g. logically partitioned system
• CPC Class Codes: G06F 2212/217 Hybrid disk, e.g. using both magnetic and solid state storage devices
• CPC Class Codes: G06F 3/061 Improving I/O performance
• CPC Class Codes: G06F 3/0655 Vertical data movement, i.e. input-output transfer; data movement between one or more hosts and one or more storage devices
• CPC Class Codes: G06F 3/0689 Disk arrays, e.g. RAID, JBOD
• CPC Class Codes: G06F 9/00 Arrangements for program control, e.g. control units program control for peripheral devices G06F13/10
• CPC Class Codes: G06F 9/45533 Hypervisors; Virtual machine monitors
• CPC Class Codes: G06F 9/45558 Hypervisor-specific management and integration aspects
• 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 9/5088 involving task migration

Abstract

A method of enabling “fast” suspend and “rapid” resume of virtual machines (VMs) employs a cache that is able to perform input/output operations at a faster rate than a storage device provisioned for the VMs. The cache may be local to a computer system that is hosting the VMs or may be shared cache commonly accessible to VMs hosted by different computer systems. The method includes the steps of saving the state of the VM to a checkpoint file stored in the cache and locking the checkpoint file so that data blocks of the checkpoint file are maintained in the cache and are not evicted, and resuming execution of the VM by reading into memory the data blocks of the checkpoint file stored in the cache.

Claims

1. In a virtualized computer system including a plurality of host computers, a first storage device accessible by the host computers, and a second storage device accessible by the host computers that has lower input/output latency and higher input/output throughput than the first storage device, a method of managing physical resources of the virtualized computer system including the first storage device and the second storage device, said method comprising:

responsive to a request to power on a VM, selecting one of the host computers in which the VM is to be powered on and reserving space in the second storage device in an amount equal to an expected size of a suspended image of the VM;

upon suspending the VM and receiving acknowledgement that the suspended image of the VM has been saved in the second storage device, decreasing an available capacity of the second storage device by the size of the suspended image of the VM; and

upon resuming the VM, increasing the available capacity of the second storage device by the size of the suspended image of the VM and reserving space in the second storage device in an amount equal to the size of the suspended image of the VM.

2. The method of claim 1, wherein the host computers include a first host computer and a second host computer and the VM is powered on in the first host computer.

3. The method of claim 2, wherein the VM is suspended while being executed in the first host computer and is to be resumed in the first host computer for execution therein.

4. The method of claim 3, wherein the second storage device includes a local solid state drive (SSD) configured in the first host computer and, upon suspending the VM, the suspended image of the VM is saved in the local SSD configured in the first host computer.

5. The method of claim 2, wherein the VM is suspended while being executed in the first host computer and is to be resumed in the second host computer for execution therein.

6. The method of claim 5, wherein the second storage device includes a shared solid state drive (SSD) accessible by the first and second host computers and, upon suspending the VM, the suspended image of the VM is saved in the shared SSD.

7. The method of claim 1, wherein the first storage device includes rotating disks and the second storage device does not include rotating disks.

8. The method of claim 1, wherein the first storage device is a disk-based storage array and the second storage device is a solid state drive (SSD).

9. The method of claim 1, further comprising:

responsive to a request to power on another VM, generating an error if a size of an unreserved space in the second storage device is less than an amount equal to an expected size of a suspended image of said another VM.

10. A non-transitory computer readable medium comprising instructions for causing a computer system to carry out a method of managing physical resources thereof, wherein the computer system includes a plurality of host computers, and the physical resources of the computer system include a first storage device accessible by the host computers, and a second storage device accessible by the host computers that has lower input/output latency and higher input/output throughput than the first storage device, said method including the steps of:

responsive to a request to power on a VM, selecting one of the host computers in which the VM is to be powered on and reserving space in the second storage device in an amount equal to an expected size of a suspended image of the VM;

upon suspending the VM and receiving acknowledgement that the suspended image of the VM has been saved in the second storage device, decreasing an available capacity of the second storage device by the size of the suspended image of the VM; and

upon resuming the VM, increasing the available capacity of the second storage device by the size of the suspended image of the VM and reserving space in the second storage device in an amount equal to the size of the suspended image of the VM.

11. The non-transitory computer readable medium of claim 10, wherein the host computers include a first host computer and a second host computer and the VM is powered on in the first host computer.

12. The non-transitory computer readable medium of claim 11, wherein the VM is suspended while being executed in the first host computer and resumed in the first host computer for execution therein.

13. The non-transitory computer readable medium of claim 10, wherein the method further includes the step of:

responsive to a request to power on another VM, generating an error if a size of an unreserved space in the second storage device is less than an amount equal to an expected size of a suspended image of said another VM.

14. A virtualized computer system comprising:

a plurality of host computers each having one or more virtual machines (VMs) running therein;

a storage device accessible by the host computers;

a cache device accessible by the host computers, the cache device having lower input/output latency and higher input/output throughput than the storage device; and

a management server configured to carry out a method of managing the cache device, the method including the steps of

responsive to a request to power on a VM, selecting one of the host computers in which the VM is to be powered on and reserving space in the cache device in an amount equal to an expected size of a suspended image of the VM;

upon suspending the VM and receiving acknowledgement that the suspended image of the VM has been saved in the second storage device, decreasing an available capacity of the second storage device by the size of the suspended image of the VM; and

upon resuming the VM, increasing the available capacity of the cache device by the size of the suspended image of the VM and reserving space in the cache device in an amount equal to the size of the suspended image of the VM.

15. The virtualized computer system of claim 14, wherein the cache device includes a local solid state drive (SSD) configured in a host computer and, upon suspending the VM, the suspended image of the VM is saved in the local SSD configured in the host computer.

16. The virtualized computer system of claim 15, wherein the VM is suspended while being executed in the host computer and resumed in another host computer for execution therein.

17. The virtualized computer system of claim 14, wherein the cache device includes a shared SSD accessible by the host computers and, upon suspending the VM, the suspended image of the VM is saved in the shared SSD.

18. The virtualized computer system of claim 17, wherein the VM is suspended while being executed in one of the host computers and resumed in another one of the host computers for execution therein.

19. The virtualized computer system of claim 14, wherein the method further includes the step of:

responsive to a request to power on another VM, generating an error if a size of an unreserved space in the cache device is less than an amount equal to an expected size of a suspended image of said another VM.