Data processing method and device and host

According to the data processing method and device and the host, the host is connected with a first storage array and a second storage array, the first storage array supports a first communication protocol, the second storage array supports a second communication protocol, the host indicates the second storage array to create a mirror image disk corresponding to a to-be-migrated disk, and the to-be-migrated disk is located in the first storage array. The mirror disk is a disk conforming to a second communication protocol; a host determines a first path for accessing a mirror image disk, the first path is a path conforming to a second communication protocol, the host sets a virtual path pointing to the first path and conforming to a first communication protocol, and the virtual path is reported to a multi-path module, so that the multi-path module sets the virtual path as an access path for accessing a to-be-migrated disk. In this way, under the condition that the host service is not interrupted, the data need