Embodiments of the present disclosure provide a method and an apparatus for a virtual machine. The method implemented in a virtual machine comprises: receiving I/O requests for I/O operations on virtual disks of the virtual machine; detecting associations between the virtual disks and virtual storage devices of a virtual machine hypervisor for the virtual machine; and scheduling the I/O requests based on the associations. Embodiments of the present disclosure enable an application-aware I/O QoS in a virtual environment in an efficiently way and moving IT solutions of virtual version to different virtual platforms. The method and apparatus according to the embodiments of the present disclosure offer good flexibility and compatibility.