On 12/23/2011 12:15 AM, Daniel P. Berrange wrote:
The 'type' attribute refers to how the host emulator deals
with the
disk.
The 'device' attribute refers to what type of device hardware is exposed
to the guest.
What we're doing here is controlling whether the host emulator allows
SG_IO. The guest visible device hardware has not changed at all. Thus
using the 'type' attribute is the correct approach.
You could also say that the host is still accessing the device in the
same way (via /dev/sdX). The guest visible device changes because in
one case it allows SG_IO, in the other it doesn't, even if the host
device is the same.
Paolo