During migration, the Migrate Virtual Machine wizard checks the destination host for compatibility with the migrating virtual machine using a number of criteria.
When you select a host or a cluster, the Compatibility panel at the bottom of the Migrate Virtual Machine wizard displays information about the compatibility of the selected host or cluster with the virtual machine’s configuration.
Compatibility Check Results
If the virtual machine is compatible, the panel displays the message Compatibility checks succeeded. If the virtual machine is not compatible with either the host’s or cluster’s configured networks or datastores, the compatibility window might display both warnings and errors:
Warning messages do not disable migration. Often the migration is justified and you can continue with the migration despite the warnings.
Errors might disable migration if no error-free destination hosts are available among the selected destination hosts. In this case, if you click Next, the wizard displays the compatibility errors again, and you cannot proceed to the next step.
Compatibility Checks During Migration Setup
When you attempt to move only the compute resource, the Migrate Virtual Machine wizard examines the source and destination hosts, the target resource pool, the datastore, and the network. When you attempt to move only the storage, the wizard checks the compatibility of the same objects except for the network.
When you move compute resources and storage together, the Migrate Virtual Machine wizard runs fewer compatibility checks. For example, if you move the compute resource, you select the target host or cluster under a vCenter Server instance. The wizard performs all necessary validation only against the selected host, and does not check the datastores available on the destination host. When you attempt to move the virtual machine to a cluster, the Migrate Virtual Machine wizard examines the compatibility against the host recommendation from vSphere DRS. The wizard directly validates the compatibility of the target datastore when you select it later.
Another compatibility check is whether vMotion is enabled on the source and target hosts.
Compatibility Checks for Virtual Hardware
Effects of a specific host CPU feature on compatibility are dependent on whether ESXi exposes or hides them from virtual machines.
Features that are exposed to virtual machines are not compatible when they are do not match on the source and target hosts.
Features that are not exposed to virtual machines are considered as compatible regardless of whether they match on the hosts.
Specific items of virtual machine hardware can also cause compatibility problems. For example, a virtual machine using an Enhanced VMXNET virtual NIC cannot be migrated to a host running a version of ESXi that does not support Enhanced VMXNET.