Abstract: A computing device is provided, which includes a volatile memory, a non-volatile memory, and a processor. A processor is configured to execute a main virtual machine for: during a detection period, detecting a cold area used by the main virtual machine from the volatile memory and the non-volatile memory; transmitting first data belonging to the cold area in the volatile memory and the non-volatile memory to a backup device; when determining that a first transmission condition is satisfied, transmitting a second data used by the main virtual machine in the volatile memory and the non-volatile memory to the backup device; and when determining that an abnormal event has occurred, notifying the abnormal event to the backup device, so as to execute a backup virtual machine in the backup device according to the first data and the second data.

Abstract: The present invention includes a main device and a backup device. A first backup system element of the main device is used to determine whether a first estimated time is less than a second estimated time. The first estimated time is a time period for directly transmitting pending data. The second estimated time is a time period for transmitting the pending data after the pending data is compressed by a current compression algorithm. If yes, the first backup system element directly transmits the pending data to a second backup system element of the backup device. If not, the first backup system element compresses the pending data by the current compression algorithm, updates the pending data and the current compression algorithm, and re-determines whether the first estimated time is less than the second estimated time. The present invention improves availability of data backup when a network bandwidth is poor.