A little while ago I wrote about how storage migration actually works. One thing I would like to call out is that the storage migration process is “copy and delete” and not “move”. Which is to say that just before storage migration is completed you will have two copies of your virtual hard disks on your computer, and the final stage of the storage migration will be to delete the original versions of the virtual hard disks.
Why I am I highlighting this?
Well, storage migration is designed to allow you to move your virtual machines from one storage location to a completely different location (i.e. a new disk, SAN or SMB share). But every now and then I find myself using storage migration just to reorganize my virtual machines and their folder structure. This can result in problems if I want to move a large virtual machine from one folder to another folder on the same disk. If I want to do this I need to make sure that I have enough space for two copies of the virtual hard disk.