Transparent host-side caching of virtual disks located on shared storage

Patent metadata

Field	Value
Publication number	US-10437727-B2
Application number	US-201815965801-A
Country	US
Kind code	B2
Filing date	Apr 27, 2018
Priority date	Aug 27, 2012
Publication date	Oct 8, 2019
Grant date	Oct 8, 2019

Abstract

Techniques for using a cache to accelerate virtual machine (VM) I/O are provided. In one embodiment, a host system can intercept an I/O request from a VM running on the host system, where the I/O request is directed to a virtual disk residing on a shared storage device. The host system can then process the I/O request by accessing a cache that resides on one or more cache devices directly attached to the host system, where the accessing of the cache is transparent to the VM.

First claim

What is claimed is:

1. A host system comprising:
a processor; and
a non-transitory computer readable medium having stored thereon program code that, when executed by the processor, causes the processor to:
intercept an I/O request from a virtual machine (VM) running on the host system, the I/O request being directed to a virtual disk of the VM; and
process the I/O request by accessing a host-side cache, wherein a guest operating system of the VM is unaware that the host-side cache is being accessed as part of the processing,

wherein the host-side cache is spread across a plurality of cache devices local to the host system, and
wherein the plurality of cache devices are pooled into at least one logical resource.

2. The host system of claim 1 wherein the plurality of cache devices include a solid state disk (SSD) device and a volatile memory device.

3. The host system of claim 1 wherein at least a portion of the plurality of cache devices are heterogeneous devices.

4. The host system of claim 1 wherein the intercepting is performed by a hypervisor of the host system.

5. The host system of claim 1 wherein the processing is implemented via a caching module that is associated with the VM, with the virtual disk, or with one or more of the plurality of cache devices.

6. The host system of claim 1 wherein the plurality of cache devices are pooled into the at least one logical resource by applying a common file system to the plurality of cache devices, and
wherein the at least one logical resource is created as a partition across the plurality of cache devices using the common file system.

7. A method for using a cache to accelerate virtual machine (VM) I/O, the method comprising:
intercepting an I/O request from a VM running on a host system, the I/O request being directed to a virtual disk of the VM; and
processing the I/O request by accessing a host-side cache, wherein a guest operating system of the VM is unaware that the host-side cache is being accessed as part of the processing,
wherein the host-side cache is spread across a plurality of cache devices local to the host system, and
wherein the plurality of cache devices are pooled into at least one logical resource.

8. The method of claim 7 wherein the plurality of cache devices include a solid state disk (SSD) device and a volatile memory device.

9. The method of claim 7 wherein at least a portion of the plurality of cache devices are heterogeneous devices.

10. The method of claim 7 wherein the intercepting is performed by a hypervisor of the host system.

11. The method of claim 7 wherein the processing is implemented via a caching module that is associated with the VM, with the virtual disk, or with one or more of the plurality of cache devices.

12. The method of claim 7 wherein the plurality of cache devices are pooled into the at least one logical resource by applying a common file system to the plurality of cache devices, and
wherein the at least one logical resource is created as a partition across the plurality of cache devices using the common file system.

13. A non-transitory computer readable storage medium having stored thereon computer software executable by a processor of a host system, the computer software embodying a method for using a host-side cache to accelerate virtual machine (VM) I/O, the method comprising:
intercepting an I/O request from a VM running on a host system, the I/O request being directed to a virtual disk of the VM; and
processing the I/O request by accessing a host-side cache, wherein a guest operating system of the VM is unaware that the host-side cache is being accessed as part of the processing,
wherein the host-side cache is spread across a plurality of cache devices local to the host system, and
wherein the plurality of cache devices are pooled into at least one logical resource.

14. The non-transitory computer readable storage medium of claim 13 wherein the plurality of cache devices include a solid state disk (SSD) device and a volatile memory device.

15. The non-transitory computer readable storage medium of claim 13 wherein at least a portion of the plurality of cache devices are heterogeneous devices.

16. The non-transitory computer readable storage medium of claim 13 wherein the intercepting is performed by a hypervisor of the host system.

17. The non-transitory computer readable storage medium of claim 13 wherein the processing is implemented via a caching module that is associated with the VM, with the virtual disk, or with one or more of the plurality of cache devices.

18. The non-transitory computer readable storage medium of claim 13 wherein the plurality of cache devices are pooled into the at least one logical resource by applying a common file system to the plurality of cache devices, and
wherein the at least one logical resource is created as a partition across the plurality of cache devices using the common file system.

Assignees

• Vmware Inc

Inventors

• Phelan Thomas A
• Rawat Mayank
• Liu Deng
• Madnani Kiran
• Bandarupalli Sambasiva

Classifications

• G06F2212/1024

  Latency reduction · CPC title

• G06F12/0866 Primary

  for peripheral storage systems, e.g. disk cache · CPC title

• G06F9/455

  Emulation; Interpretation; Software simulation, e.g. virtualisation or emulation of application or operating system execution engines · CPC title

• G06F2009/45579

  I/O management, e.g. providing access to device drivers or storage · CPC title

• G06F3/061

  Improving I/O performance · CPC title