A storage device includes; a first memory subsystem including a first nonvolatile memory device (NVM), a first storage controller configured to control operation of the first NVM, and a first resource, and a second memory subsystem including a second NVM, a second storage controller configured to control operation of the second NVM, and a second resource, wherein the first resource is a shared resource useable by the second memory subsystem, and the second resource is shared resource useable by the first memory subsystem.