A method comprising providing, by a virtual manager entity of a virtual network environment, a notification of requested snapshot creation of a resource of a virtual machine entity in the virtual network environment for the virtual machine entity, the notification of requested snapshot creation being triggered by an automatic event or a manual event at the virtual manager entity or another entity communicatively coupled to the virtual manager entity, obtaining, at the virtual manager entity, a result of snapshot preparation processing by the virtual machine entity, wherein the snapshot preparation result indicates whether the virtual machine entity has performed or denied preparation for the requested snapshot creation, and executing, by the virtual manager entity, snapshot processing on the basis of the obtained snapshot preparation result, said snapshot processing comprising: when the snapshot preparation result indicates that the virtual machine entity has performed preparation for the requested snapshot creation, creating the requested snapshot, providing a notification of completed snapshot creation after creating the requested snapshot, and obtaining a snapshot preparation cancellation notification from the virtual machine entity, wherein the snapshot preparation cancellation notification notifies the virtual manager entity that the virtual machine entity operates normally again, and when the snapshot preparation result indicates that the virtual machine entity has denied preparation for the requested snapshot creation, rejecting the requested snapshot, wherein the requested snapshot refers to information relating to a network element virtualized in the virtual machine entity. providing, by a virtual manager entity of a virtual network environment, a notification of requested snapshot creation of a resource of a virtual machine entity in the virtual network environment for the virtual machine entity, the notification of requested snapshot creation being triggered by an automatic event or a manual event at the virtual manager entity or another entity communicatively coupled to the virtual manager entity, obtaining, at the virtual manager entity, a result of snapshot preparation processing by the virtual machine entity, wherein the snapshot preparation result indicates whether the virtual machine entity has performed or denied preparation for the requested snapshot creation, and executing, by the virtual manager entity, snapshot processing on the basis of the obtained snapshot preparation result, said snapshot processing comprising: when the snapshot preparation result indicates that the virtual machine entity has performed preparation for the requested snapshot creation, creating the requested snapshot, providing a notification of completed snapshot creation after creating the requested snapshot, and obtaining a snapshot preparation cancellation notification from the virtual machine entity, wherein the snapshot preparation cancellation notification notifies the virtual manager entity that the virtual machine entity operates normally again, and when the snapshot preparation result indicates that the virtual machine entity has denied preparation for the requested snapshot creation, rejecting the requested snapshot, when the snapshot preparation result indicates that the virtual machine entity has performed preparation for the requested snapshot creation, creating the requested snapshot, providing a notification of completed snapshot creation after creating the requested snapshot, and obtaining a snapshot preparation cancellation notification from the virtual machine entity, wherein the snapshot preparation cancellation notification notifies the virtual manager entity that the virtual machine entity operates normally again, and when the snapshot preparation result indicates that the virtual machine entity has denied preparation for the requested snapshot creation, rejecting the requested snapshot, wherein the requested snapshot refers to information relating to a network element virtualized in the virtual machine entity.