@task
@roles('db')
def prepare_dbstorage(
    additional_disks=None,
    mount_point_backups='/var/backups',
    mount_point_postgresql='/var/lib/postgresql',
    device_name_backups='/dev/vdb1',
    device_name_postgresql='/dev/vdb1',
    cloudless=False,
):
    """
    Format new partitions and mount, now and permanently
    for dbserver's backups and postgres
    """
    if additional_disks is None:
        additional_disks = env.buildparams.get('additional_disks_db', None)
    if additional_disks is None:
        # Single disk installation - nothing to do for db storage
        return None

    # Stop PostgreSQL while we're working with its data directories
    with settings(warn_only=True):
        # Postgres may not be running at this point in time (e.g. cloudless)
        sudo('service postgresql stop')

    # FIXME: do we really know which will be /dev/vdb and which /dev/vdc (async timing)

    # /var/backups: exists but is empty at this stage - just mount
    # cloudless vm does not need a backup
    if not cloudless:
        sudo('echo -e "o\\nn\\np\\n1\\n\\n\\nw\\n" | fdisk {}'.format(device_name_backups))
        sudo('mkfs.ext4 {}'.format(device_name_backups))
        # append to root-only writable file, suppress output (can't just sudo with >>):
        sudo(
            'echo "{}         {} ext4   defaults        0 0" | sudo tee --append /etc/fstab > /dev/null'.format(
                device_name_backups,
                mount_point_backups
            )
        )
        sudo('mount {}'.format(mount_point_backups))

    # /var/lib/postgresql: we know mount point already exists, move away
    sudo('mv {} {}_ORIG'.format(mount_point_postgresql, mount_point_postgresql))
    sudo('mkdir {}'.format(mount_point_postgresql))

    # Cloudless server has disk set up differently
    # Does not need a new disk created
    # Needs fstab to use UUID of disk manually created disk (by a sysadmin)
    if cloudless:
        postgres_device_uuid = env.buildparams['postgres_device_uuid']
        sudo(
            'echo "UUID={} {} ext4  defaults  0 2" | sudo tee --append /etc/fstab > /dev/null'.format(
                postgres_device_uuid,
                mount_point_postgresql,
            )
        )
    else:
        sudo('echo -e "o\\nn\\np\\n1\\n\\n\\nw\\n" | fdisk {}'.format(device_name_postgresql))
        sudo('mkfs.ext4 {}'.foramt(device_name_postgresql))
        # append to root-only writable file, suppress output (can't just sudo with >>):
        sudo(
            'echo "{}         {} ext4   defaults        0 0" | sudo tee --append /etc/fstab > /dev/null'.format(
                device_name_postgresql, mount_point_postgresql
            )
        )
    sudo('mount {}'.format(mount_point_postgresql))
    sudo('chown postgres:postgres {}'.format(mount_point_postgresql))
    sudo('mv {}_ORIG/* {}'.format(mount_point_postgresql, mount_point_postgresql))
    # also copy hidden files like .pgpass (start with . but not the parent dir ..)
    # move breaks with inter_device copy on cloudless vm
    sudo('cp -R {}_ORIG/.[!.]* {}'.format(mount_point_postgresql, mount_point_postgresql))
    sudo('rm -rf {}_ORIG'.format(mount_point_postgresql))

    sudo('service postgresql start')