You can migrate disks of your virtual servers to other data stores, which are allocated to the same compute resource or compute zone. Unlike VS migration – disk migration requires reboot of the VS (despite the template it is based on).
To migrate a disk:

  1. Go to your Control Panel > Cloud > Virtual Servers menu.
  2. Make sure your virtual server is powered off, then click its label to open its details screen.
  3. Click the Storage tab > Disks.
  4. Click the Actions button next to the disk you want to move to another data store, then click the Import link.

  5. On the screen that appears, select a target data store from the drop-down box.

    You can only migrate disks to data stores in data store zones assigned to your billing plan.

  6. Click Start Migrate. 

    You cannot migrate a disk to a data store with less capacity than the disk size!
    If you move an 850 GB disk between aggregates with 10 GB actual usage, the 'dd' image of the local volume manager will take 850 GB space, because the entire local volume manager is copied, including zero 'd space which may not be able to be recovered.