While reading this article on the technet.com website I once again noticed the way Microsoft does it’s marketing. Look for the table which shows the features of Microsoft’s Quick Storage Migration and VMware vMotion.
It compares the old, not avialable for sale VMware ESX 3.5 with the not yet available VMM 2008 R2 and Hyper-V R2. Storage vMotion has been added to the vCenter 4 interface. The most important feature of storage migration is not listed in the table: being able to migrate a virtual machine to different storage without downtime!
Storage vMotion does this, Quick Storage Migration will pause your virtual machine.