'Calculate available space on the NFS share.
:param nfs_share: example 172.18.194.100:/var/nfs'

def _get_capacity_info(self, nfs_share):

    nms = self.share2nms[nfs_share]
    (ns_volume, ns_folder) = self._get_share_datasets(nfs_share)
    folder_props = nms.folder.get_child_props(('%s/%s' % (ns_volume, ns_folder)), 'used|available')
    free = utils.str2size(folder_props['available'])
    allocated = utils.str2size(folder_props['used'])
    self.shares_with_capacities[nfs_share] = {'free': utils.str2gib_size(free), 'total': utils.str2gib_size((free + allocated))}
    return ((free + allocated), free, allocated)
