Setting up vnd devices for disks

[Louis Guillaume <louis%zabrico.com@localhost>]

Hi,

I'm setting up my dom0 and would like to organize all the disk space for 
the hosted domains in one place (/srv/xen). And I want to do it in the 
most flexible and/or efficient way.

From what I understand we can use vnd devices for disks in our guest 
environments and this is somehow a good thing. But why? Since there's 
not too much info on this topic out there, from what I can tell, I have 
a few questions:

o What benefits do we gain from using vnd devices in our xen
  configurations over regular files?

o What's the correct practice for managing vnd devices? Other than
  having a script to vnconfig them each time we boot, how should
  these be tracked?

Any help clarifying this would be great. I'm using netbsd-5/amd64 for 
dom0 with a recent xenkernel33 and xentools33.

Louis