code: func (r Virtual_Guest) CheckHostDiskAvailability(diskCapacity *int) (resp bool, err error) {
  	params := []interface{}{
  		diskCapacity,
  	}
  	err = r.Session.DoRequest("SoftLayer_Virtual_Guest", "checkHostDiskAvailability", params, &r.Options, &resp)
  	return
  }
docs: // Checks the associated host for available disk space to determine if guest migration is necessary. This method is only used with local disks. If this method returns false, calling attachDiskImage($imageId) will automatically migrate the destination guest to a new host before attaching the portable volume.