This check case `df -T ${WORKDIR}` in */dev/md[0-9]* | *tmpfs*) echo -n "`basename $0`: " echo -n "${_WORKDIR_bad2}" echo ${WORKDIR} exit 1 ;; esac is IMHO not necessary and even harmful. It prevents from updating a chrooted system mounted from a disk image. Could we reconsider and remove it?