I/O
Storage Stack
In this example storage stack, there is a VirtIODisk (viodisk0) at the root of the stack, which interfaces directly with the hardware (and - not pictured - below it would be a PCIDevice.) An attached Disk (dk0) provides the standard conveniences. Attached to dk0 is a VolumeManager, which has detected two GPT partitions and created and attached two Volumes (ld0s1 and ld0s2).