US Patent 11262953 Image file optimizations by opportunistic sharing

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.