I often get asked what is the share image file instead of copying it option for in SCVMM 2012.
The option is available when attaching an ISO file to a VM,
Well in SCVMM when you attach an image/ISO file to a vm the file is copied to the folder where the VM is stored.
This is both time and space consuming. Ticking the share image file instead of copying it will override this behaviour and directly attach the image file to the VM. It’s best to have all your Image files stored in a SCVMM library to guarantee that this works.