Code offered by Tommaso in 2021 could be changed to " if [ "${CONF_MAXDISK_PCT}" != "" ] ; then # check for free disk size percentage and don't overstep it AVAIL_KB=$(/bin/df --output=avail "$(dirname "${CONF_SWAPFILE}")/." | tail -1) if [ -n "${CONF_SWAPFILE}" -a -e "${CONF_SWAPFILE}" ]; then CURRENT_SIZE_B=$(stat --printf='%s' "${CONF_SWAPFILE}") AVAIL_KB=$(echo "${AVAIL_KB} ${CURRENT_SIZE_B} 1024 / + p" | dc) fi MAX_AVAIL_MB=$(echo "${AVAIL_KB} 1024 / ${CONF_MAXDISK_PCT} * 100 / p" | dc) if [ "${CONF_SWAPSIZE}" -gt "${MAX_AVAIL_MB}" ] ; then echo -n ", restricting to ${CONF_MAXDISK_PCT}% of remaining disk size: ${MAX_AVAIL_MB}MBytes" CONF_SWAPSIZE="${MAX_AVAIL_MB}" fi fi " This works for me Thanks Mike