Image file optimizations by opportunistic sharing

Patent metadata

Field	Value
Publication number	US-11262953-B2
Application number	US-202016752305-A
Country	US
Kind code	B2
Filing date	Jan 24, 2020
Priority date	Jan 24, 2020
Publication date	Mar 1, 2022
Grant date	Mar 1, 2022

Abstract

Container images are fetched in a clustered container host system with a shared storage device. Fetching a first container image in a first virtual machine includes creating a first virtual disk in the shared storage device, storing an image of the first container in the first virtual disk, mounting the first virtual disk to the first virtual machine, and updating a metadata cache to associate the image of the first container to the first virtual disk. Fetching a second container image in a second virtual machine includes checking the metadata cache to determine that a portion of the image of the second container is stored in the first virtual disk, creating a second virtual disk in the shared storage device, adding a reference to the first virtual disk in a metadata of the second virtual disk, and mounting the second virtual disk to the second virtual machine.

First claim

What is claimed is:

1. A method of fetching container images in a clustered container host system comprising a plurality of hosts that share a storage device, wherein the hosts include a virtualization software layer that support execution of virtual machines in the hosts, and one or more virtual machines has implemented therein a container engine that supports execution of containers within the respective virtual machines, said method comprising:
in connection with deploying a first container in a first virtual machine, creating a first virtual disk in the storage device, storing an image of the first container in the first virtual disk, mounting the first virtual disk to the first virtual machine, and updating a metadata cache to associate the image of the first container to the first virtual disk; and
in connection with deploying a second container in a second virtual machine, checking the metadata cache to determine that a portion of the image of the second container is stored in the first virtual disk, creating a second virtual disk in the storage device, adding a reference to the first virtual disk in a metadata of the second virtual disk, and mounting the second virtual disk to the second virtual machine.

2. The method of claim 1 , wherein the image of the second container comprises a plurality of layers arranged top to bottom in a hierarchy and the portion of the image of the second container that is stored in the first virtual disk includes one or more uppermost layers in the hierarchy.

3. The method of claim 2 , wherein the portion of the image of the second container is identical to the image of the first container.

4. The method of claim 3 , wherein the first and second virtual machines are running in different hosts.

5. The method of claim 3 , wherein the first and second virtual machines are the same virtual machine.

6. The method of claim 1 , wherein the first and second virtual machines are pods of a Kubernetes system and the hosts are nodes of a Kubernetes cluster.

7. The method of claim 1 , further comprising:
in connection with deploying a third container in a third virtual machine, checking the metadata cache to determine that a portion of the image of the third container overlaps with a portion of the image of the first container stored in the first virtual disk, creating third and fourth virtual disks in the storage device, fetching data into the third and fourth virtual disks, adding a reference to the third virtual disk in a metadata of the fourth virtual disk, and mounting the fourth virtual disk to the third virtual machine.

8. The method of claim 7 , wherein the data fetched into the third virtual disk is data of the overlapping portion of the images of the first and third containers, and the data fetched into the fourth virtual disk is data of the non-overlapping portion of the image of the third container.

9. The method of claim 8 , wherein the image of the third container comprises a plurality of layers arranged top to bottom in a hierarchy and the portion of the image of the third container that is stored in the third virtual disk includes one or more uppermost layers in the hierarchy.

10. The method of claim 9 , further comprising:
in connection with deploying a fourth container in a fourth virtual machine, checking the metadata cache to determine that a portion of the image of the fourth container is stored in the third virtual disk, creating a fifth virtual disk, adding a reference to the third virtual disk in a metadata of the fifth virtual disk, and mounting the fifth virtual disk to the fourth virtual machine.

11. A non-transitory computer readable medium comprising instructions to be executed in a computing device to cause the computing device to carry out a method of fetching container images in a clustered container host system with a shared storage device, wherein hosts include a virtualization software layer that support execution of virtual machines in the hosts, and one or more virtual machines has implemented therein a container engine that supports execution of containers within the respective virtual machines, said method comprising:
in connection with deploying a first container in a first virtual machine, creating a first virtual disk in the shared storage device, storing an image of the first container in the first virtual disk, mounting the first virtual disk to the first virtual machine, and updating a metadata cache to associate the image of the first container to the first virtual disk; and
in connection with deploying a second container in a second virtual machine, checking the metadata cache to determine that a portion of the image of the second container is stored in the first virtual disk, creating a second virtual disk in the shared storage device, adding a reference to the first virtual disk in a metadata of the second virtual disk, and mounting the second virtual disk to the second virtual machine.

12. The non-transitory computer readable medium of claim 11 , wherein the image of the second container comprises a plurality of layers arranged top to bottom in a hierarchy and the portion of the image of the second container that is stored in the first virtual disk includes one or more uppermost layers in the hierarchy.

13. The non-transitory computer readable medium of claim 12 , wherein the portion of the image of the second container is identical to the image of the first container.

14. The non-transitory computer readable medium of claim 13 , wherein the first and second virtual machines are running in different hosts.

15. The non-transitory computer readable medium of claim 13 , wherein the first and second virtual machines are the same virtual machine.

16. The non-transitory computer readable medium of claim 11 , wherein the first and second virtual machines are pods of a Kubernetes system and the hosts are nodes of a Kubernetes cluster.

17. The non-transitory computer readable medium of claim 11 , wherein the method further comprises:
in connection with deploying a third container in a third virtual machine, checking the metadata cache to determine that a portion of the image of the third container overlaps with a portion of the image of the first container stored in the first virtual disk, creating third and fourth virtual disks in the shared storage device, fetching data into the third and fourth virtual disks, adding a reference to the third virtual disk in a metadata of the fourth virtual disk, and mounting the fourth virtual disk to the third virtual machine.

18. The non-transitory computer readable medium of claim 17 , wherein
the data fetched into the third virtual disk is data of the overlapping portion of the images of the first and third containers, and the data fetched into the fourth virtual disk is data of the non-overlapping portion of the image of the third container, and
the image of the third container comprises a plurality of layers arranged top to bottom in a hierarchy and the portion of the image of the third container that is stored in the third virtual disk includes one or more uppermost layers in the hierarchy.

19. A clustered container host system comprising:
a storage device; and
a plurality of hosts that share the storage device, wherein the hosts each include a virtualization software layer that supports execution of virtual machines (VMs) therein, and one or more VMs are pod VMs that have implemented therein a container engine that supports execution of containers within the respective pod VMs, wherein
in connection with deploying a first containe

Assignees

• Vmware Inc

Inventors

• Corrie Benjamin J
• Kumar Harsh

Classifications

• G06F2009/45562

  Creating, deleting, cloning virtual machine instances · CPC title

• G06F3/0665 Primary

  at area level, e.g. provisioning of virtual or logical volumes · CPC title

• G06F2009/45595

  Network integration; Enabling network access in virtual machine instances · CPC title

• G06F9/45558 Primary

  Hypervisor-specific management and integration aspects · CPC title

• G06F3/067

  Distributed or networked storage systems, e.g. storage area networks [SAN], network attached storage [NAS] · CPC title