Patent ID: 9058196
Filing Date: 2015-06-16
Classification: G06F

Abstract:
1. A method comprising: receiving a command to start a virtual machine, the virtual machine having a read-only layer and a copy-on-write (COW) layer; remotely accessing the COW layer of the virtual machine from a network storage; determining whether the read-only layer of the virtual machine is cached in a local storage; upon determining that the read-only layer of the virtual machine is cached in the local storage, starting, by a processing device, the virtual machine in view of a combination of the remotely accessed COW layer and the cached read-only layer of the virtual machine, wherein the COW layer comprises a first link to check for the read-only layer stored in the local storage and a second link to a copy of the read-only layer stored in the network storage, and wherein the read-only layer comprises a third link to check for one of an additional read-only layer or a base read-only layer stored in the local storage and a forth link to check for one of a copy of the additional read-only layer or a copy of the base read-only layer stored in the network storage; and in response to receiving a command to generate a point-in-time copy of the virtual machine in view of exceeding a threshold amount of changes, designating the COW layer as a new read-only layer and generating a new COW layer that links to the new read-only layer in the local storage and the new read-only layer in the network storage.