You can move virtual machines from one host or storage location to another location using hot or cold migration. For example, with vMotion you can move powered on virtual machines away from a host to perform maintenance, to balance loads, to collocate virtual machines that communicate with each other, to move virtual machines apart to minimize fault domain, to migrate to new server hardware, and so on.
- Cold Migration
- You can move a powered off or suspended virtual machine to a new host. Optionally, you can relocate configuration and disk files for powered off or suspended virtual machines to new storage locations. You can also use cold migration to move virtual machines from one datacenter to another. To perform a cold migration, you can move virtual machines manually or set up a scheduled task.
- Hot Migration
- Depending on the type of migration you are using, vMotion or Storage vMotion, you can move a turned on virtual machine to a different host, or move its disks or folder to a different datastore without any interruption in the availability of the virtual machine. vMotion is also referred to as live migration or hot migration.
- You cannot move a powered on virtual machine from one datacenter to another.
In vCenter Server, you have the following migration options:
- Change Host
- Moving a virtual machine, but not its storage to another host. You can move the virtual machine using cold migration or hot migration. You use vMotion to move a powered on virtual machine to another host.
- Change Datastore
- Moving a virtual machine and its storage, including virtual disks and configuration files or a combination of these, to a new datastore on the same host. You can change the datastore using cold or hot migration. You use Storage Migration to move a powered on virtual machine and its storage to a new datastore.
- Change Host and Datastore
- Moving a virtual machine to another host and moving its disk or virtual machine folder to another datastore. You can change the host and datastore using cold or hot migration. Hot migration is a combination of Storage vMotion and vMotion.
To migrate virtual machines with disks larger than 2TB, the source and destination hosts must run ESXi 5.5 or later.