[VMonG5K] Add strategy keyword
This gouverns how the disk image will be created. Currently we support:
-
copy:
image
will be copied in theworking_dir
. Then a copy will be made for every single vm that need to boot on the current host. (that makes n+1 copy of the base image) -
cow:
image
will be copied in theworking_dir
. Then a copy on write file is created for every single vm that need to boot on the current host.