Virtual Drives for Testing

[Randall Smith <randall@tnr.cc>]

I'd like to test different drive configurations virtually without having 
to resort to something like vmware or qemu.  I know how to create a 
virtual filesystem using dd and wonder can I create a virtual drive that 
I can partition with fdisk, etc.  For example, I'd like to set up a 
virtual raid 5 array.  Can this be easily done?

Randall