Users Guide

16 Storage Solutions Guide
Figure 6. VHD I/O Path
Passthrough
The disk I/O request flows from the guest application through the storage
stack of the guest OS and into the parent partition. Unlike VHDs that have a
file system, volume, and disk partition in the parent partition, the
passthrough disk is a raw device. Therefore, the I/O request is routed directly
into the remainder of the parent partition's storage stack and onto the
physical device.