#!/bin/sh
zfs destroy $1@weekly.4 > /dev/null 2>&1
zfs rename $1@weekly.3 @weekly.4 > /dev/null 2>&1
zfs rename $1@weekly.2 @weekly.3 > /dev/null 2>&1
zfs rename $1@weekly.1 @weekly.2 > /dev/null 2>&1
zfs snapshot $1@weekly.1