A virtual machine and its host must meet resource and configuration requirements for the virtual machine disks to be migrated with Storage VMotion.

Storage VMotion is subject to the following requirements and limitations:

Virtual machines with snapshots cannot be migrated using Storage VMotion.

Virtual machine disks must be in persistent mode or be raw device mappings (RDMs). For virtual compatibility mode RDMs, you can migrate the mapping file or convert to thick-provisioned or thin-provisioned disks during migration as long as the destination is not an NFS datastore. For physical compatibility mode RDMs, you can migrate the mapping file only.

Migration of virtual machines during VMware Tools installation is not supported.

The host on which the virtual machine is running must have a license that includes Storage VMotion.

ESX/ESXi 3.5 hosts must be licensed and configured for VMotion. ESX/ESXi 4.0 and later hosts do not require VMotion configuration in order to perform migration with Storage VMotion.

The host on which the virtual machine is running must have access to both the source and target datastores.

A particular host can be involved in up to two migrations with VMotion or Storage VMotion at one time.

vSphere supports a maximum of eight simultaneous VMotion, cloning, deployment, or Storage VMotion accesses to a single VMFS3 datastore, and a maximum of four simultaneous VMotion, cloning, deployment, or Storage VMotion accesses to a single NFS or VMFS2 datastore. A migration with VMotion involves one access to the datastore. A migration with Storage VMotion involves one access to the source datastore and one access to the destination datastore.