A memory system is provided to include a first virtual function controller in communication with a first virtual machine of a host and configured to receive, from the first virtual machine, a command for accessing a namespace and provide, to the first virtual machine, a response to the command; a second virtual function controller in communication with a second virtual machine of the host and configured to be coupled to the namespace and receive the command from the first virtual function controller based on status information of the first virtual function controller and the second virtual function controller; a buffer memory configured to provide an area for data corresponding to the command; and a memory controller configured to access the namespace based on the command and provide the buffer memory with the data.