diff --git a/Dockerfile b/Dockerfile
index 2e53149..9110925 100644
--- a/Dockerfile
+++ b/Dockerfile
@@ -7,7 +7,7 @@ RUN apt-get -y update && \
         git vim parted \
         quilt coreutils qemu-user-static debootstrap zerofree zip dosfstools \
         bsdtar libcap2-bin rsync grep udev xz-utils curl xxd file kmod bc\
-        binfmt-support ca-certificates \
+        binfmt-support ca-certificates qemu-utils kpartx \
     && rm -rf /var/lib/apt/lists/*
 
 COPY . /pi-gen/
diff --git a/README.md b/README.md
index 29d8166..388a61f 100644
--- a/README.md
+++ b/README.md
@@ -14,7 +14,8 @@ To install the required dependencies for pi-gen you should run:
 
 ```bash
 apt-get install coreutils quilt parted qemu-user-static debootstrap zerofree zip \
-dosfstools bsdtar libcap2-bin grep rsync xz-utils file git curl bc
+dosfstools bsdtar libcap2-bin grep rsync xz-utils file git curl bc \
+qemu-utils kpartx
 ```
 
 The file `depends` contains a list of tools needed.  The format of this
@@ -36,7 +37,30 @@ The following environment variables are supported:
    but you should use something else for a customized version.  Export files
    in stages may add suffixes to `IMG_NAME`.
 
- * `RELEASE` (Default: buster)
+* `USE_QCOW2`(Default: `1` )
+
+    Instead of using traditional way of building the rootfs of every stage in
+    single subdirectories and copying over the previous one to the next one,
+    qcow2 based virtual disks with backing images are used in every stage.
+    This speeds up the build process and reduces overall space consumption
+    significantly.
+
+    <u>Additional optional parameters regarding qcow2 build:</u>
+
+    * `BASE_QCOW2_SIZE` (Default: 12G)
+
+        Size of the virtual qcow2 disk.
+        Note: it will not actually use that much of space at once but defines the
+        maximum size of the virtual disk. If you change the build process by adding
+        a lot of bigger packages or additional build stages, it can be necessary to
+        increase the value because the virtual disk can run out of space like a normal
+        hard drive would.
+
+    **CAUTION:**  Although the qcow2 build mechanism will run fine inside Docker, it can happen
+    that the network block device is not disconnected correctly after the Docker process has
+    ended abnormally. In that case see [Disconnect an image if something went wrong](#Disconnect-an-image-if-something-went-wrong)
+
+* `RELEASE` (Default: buster)
 
    The release version to build images against. Valid values are jessie, stretch
    buster, bullseye, and testing.
@@ -328,6 +352,71 @@ follows:
  * Once you're happy with the image you can remove the SKIP_IMAGES files and
    export your image to test
 
+# Regarding Qcow2 image building
+
+### Get infos about the image in use
+
+If you issue the two commands shown in the example below in a second command shell while a build
+is running you can find out, which network block device is currently being used and which qcow2 image
+is bound to it.
+
+Example:
+
+```bash
+root@build-machine:~/$ lsblk | grep nbd
+nbd1      43:32   0    10G  0 disk 
+├─nbd1p1  43:33   0    10G  0 part 
+└─nbd1p1 253:0    0    10G  0 part
+
+root@build-machine:~/$ ps xa | grep qemu-nbd
+ 2392 pts/6    S+     0:00 grep --color=auto qemu-nbd
+31294 ?        Ssl    0:12 qemu-nbd --discard=unmap -c /dev/nbd1 image-stage4.qcow2
+```
+
+Here you can see, that the qcow2 image `image-stage4.qcow2` is currently connected to `/dev/nbd1` with
+the associated partition map `/dev/mapper/nbd1p1`. Don't worry that `lsblk` shows two entries. It is totally fine, because the device map is accessible via `/dev/mapper/nbd1p1` and also via `/dev/dm-0`. This is all part of the device mapper functionality of the kernel. See `dmsetup` for further information.
+
+### Mount a qcow2 image
+
+If you want to examine the content of a a single stage, you can simply mount the qcow2 image found in the `WORK_DIR` directory with the tool `./imagetool.sh`.
+
+See `./imagetool.sh -h` for further details on how to use it.
+
+### Disconnect an image if something went wrong
+
+It can happen, that your build stops in case of an error. Normally `./build.sh` should handle image disconnection appropriately, but in rare cases, especially during a Docker build, this may not work as expected. If that happens, starting a new build will fail and you may have to disconnect the image and/or device yourself.
+
+A typical message indicating that there are some orphaned device mapper entries is this:
+
+```
+Failed to set NBD socket 
+Disconnect client, due to: Unexpected end-of-file before all bytes were read
+```
+
+If that happens go through the following steps:
+
+1. First, check if the image is somehow mounted to a directory entry and umount it as you would any other block device, like i.e. a hard disk or USB stick.
+
+2. Second, to disconnect an image from `qemu-nbd`, the QEMU Disk Network Block Device Server, issue the following command (be sure to change the device name to the one actually used):
+
+   ```bash
+   sudo qemu-nbd -d /dev/nbd1
+   ```
+
+   Note: if you use Docker build, normally no active `qemu-nbd` process exists anymore as it will be terminated when the Docker container stops.
+
+3. To disconnect a device partition map from the network block device, execute:
+
+   ```bash
+   sudo kpartx -d /dev/nbd1
+   or
+   sudo ./imagetool.sh --cleanup
+   ```
+   
+   Note: The `imagetool.sh` command will cleanup any /dev/nbdX that is not connected to a running `qemu-nbd` daemon. Be careful if you use network block devices for other tasks utilizing NBDs on your build machine as well.
+
+Now you should be able to start a new build without running into troubles again. Most of the time, especially when using Docker build, you will only need no. 3 to get everything up and running again. 
+
 # Troubleshooting
 
 ## `64 Bit Systems`
diff --git a/build-docker.sh b/build-docker.sh
index b6a9ea3..aba71e6 100755
--- a/build-docker.sh
+++ b/build-docker.sh
@@ -1,4 +1,5 @@
 #!/bin/bash -eu
+
 DIR="$( cd "$( dirname "${BASH_SOURCE[0]}" )" >/dev/null 2>&1 && pwd )"
 
 BUILD_OPTS="$*"
@@ -77,6 +78,9 @@ ${DOCKER} build -t pi-gen "${DIR}"
 if [ "${CONTAINER_EXISTS}" != "" ]; then
 	trap 'echo "got CTRL+C... please wait 5s" && ${DOCKER} stop -t 5 ${CONTAINER_NAME}_cont' SIGINT SIGTERM
 	time ${DOCKER} run --rm --privileged \
+		--cap-add=ALL \
+		-v /dev:/dev \
+		-v /lib/modules:/lib/modules \
 		--volume "${CONFIG_FILE}":/config:ro \
 		-e "GIT_HASH=${GIT_HASH}" \
 		--volumes-from="${CONTAINER_NAME}" --name "${CONTAINER_NAME}_cont" \
@@ -88,6 +92,9 @@ if [ "${CONTAINER_EXISTS}" != "" ]; then
 else
 	trap 'echo "got CTRL+C... please wait 5s" && ${DOCKER} stop -t 5 ${CONTAINER_NAME}' SIGINT SIGTERM
 	time ${DOCKER} run --name "${CONTAINER_NAME}" --privileged \
+		--cap-add=ALL \
+		-v /dev:/dev \
+		-v /lib/modules:/lib/modules \
 		--volume "${CONFIG_FILE}":/config:ro \
 		-e "GIT_HASH=${GIT_HASH}" \
 		pi-gen \
@@ -96,6 +103,7 @@ else
 	rsync -av work/*/build.log deploy/" &
 	wait "$!"
 fi
+
 echo "copying results from deploy/"
 ${DOCKER} cp "${CONTAINER_NAME}":/pi-gen/deploy .
 ls -lah deploy
diff --git a/build.sh b/build.sh
index a8247ab..c00555a 100755
--- a/build.sh
+++ b/build.sh
@@ -1,4 +1,5 @@
 #!/bin/bash -e
+
 # shellcheck disable=SC2119
 run_sub_stage()
 {
@@ -13,7 +14,7 @@ $(cat "${i}-debconf")
 SELEOF
 EOF
 
-		log "End ${SUB_STAGE_DIR}/${i}-debconf"
+			log "End ${SUB_STAGE_DIR}/${i}-debconf"
 		fi
 		if [ -f "${i}-packages-nr" ]; then
 			log "Begin ${SUB_STAGE_DIR}/${i}-packages-nr"
@@ -22,6 +23,11 @@ EOF
 				on_chroot << EOF
 apt-get -o APT::Acquire::Retries=3 install --no-install-recommends -y $PACKAGES
 EOF
+				if [ "${USE_QCOW2}" = "1" ]; then
+					on_chroot << EOF
+apt-get clean
+EOF
+				fi
 			fi
 			log "End ${SUB_STAGE_DIR}/${i}-packages-nr"
 		fi
@@ -32,6 +38,11 @@ EOF
 				on_chroot << EOF
 apt-get -o APT::Acquire::Retries=3 install -y $PACKAGES
 EOF
+				if [ "${USE_QCOW2}" = "1" ]; then
+					on_chroot << EOF
+apt-get clean
+EOF
+				fi
 			fi
 			log "End ${SUB_STAGE_DIR}/${i}-packages"
 		fi
@@ -82,17 +93,30 @@ EOF
 run_stage(){
 	log "Begin ${STAGE_DIR}"
 	STAGE="$(basename "${STAGE_DIR}")"
+
 	pushd "${STAGE_DIR}" > /dev/null
-	unmount "${WORK_DIR}/${STAGE}"
+
 	STAGE_WORK_DIR="${WORK_DIR}/${STAGE}"
 	ROOTFS_DIR="${STAGE_WORK_DIR}"/rootfs
+
+	if [ "${USE_QCOW2}" = "1" ]; then 
+		if [ ! -f SKIP ]; then
+			load_qimage
+		fi
+	else
+		# make sure we are not umounting during export-image stage
+		if [ "${USE_QCOW2}" = "0" ] && [ "${NO_PRERUN_QCOW2}" = "0" ]; then
+			unmount "${WORK_DIR}/${STAGE}"
+		fi
+	fi
+	
 	if [ ! -f SKIP_IMAGES ]; then
 		if [ -f "${STAGE_DIR}/EXPORT_IMAGE" ]; then
 			EXPORT_DIRS="${EXPORT_DIRS} ${STAGE_DIR}"
 		fi
 	fi
 	if [ ! -f SKIP ]; then
-		if [ "${CLEAN}" = "1" ]; then
+		if [ "${CLEAN}" = "1" ] && [ "${USE_QCOW2}" = "0" ] ; then
 			if [ -d "${ROOTFS_DIR}" ]; then
 				rm -rf "${ROOTFS_DIR}"
 			fi
@@ -103,13 +127,21 @@ run_stage(){
 			log "End ${STAGE_DIR}/prerun.sh"
 		fi
 		for SUB_STAGE_DIR in "${STAGE_DIR}"/*; do
-			if [ -d "${SUB_STAGE_DIR}" ] &&
-			   [ ! -f "${SUB_STAGE_DIR}/SKIP" ]; then
+			if [ -d "${SUB_STAGE_DIR}" ] && [ ! -f "${SUB_STAGE_DIR}/SKIP" ]; then
 				run_sub_stage
 			fi
 		done
 	fi
-	unmount "${WORK_DIR}/${STAGE}"
+
+	if [ "${USE_QCOW2}" = "1" ]; then 
+		unload_qimage
+	else
+		# make sure we are not umounting during export-image stage
+		if [ "${USE_QCOW2}" = "0" ] && [ "${NO_PRERUN_QCOW2}" = "0" ]; then
+			unmount "${WORK_DIR}/${STAGE}"
+		fi
+	fi
+
 	PREV_STAGE="${STAGE}"
 	PREV_STAGE_DIR="${STAGE_DIR}"
 	PREV_ROOTFS_DIR="${ROOTFS_DIR}"
@@ -143,6 +175,15 @@ do
 	esac
 done
 
+term() {
+	if [ "${USE_QCOW2}" = "1" ]; then
+		log "Unloading image"
+		unload_qimage
+	fi
+}
+
+trap term EXIT INT TERM
+
 export PI_GEN=${PI_GEN:-pi-gen}
 export PI_GEN_REPO=${PI_GEN_REPO:-https://github.com/RPi-Distro/pi-gen}
 
@@ -208,6 +249,18 @@ source "${SCRIPT_DIR}/common"
 # shellcheck source=scripts/dependencies_check
 source "${SCRIPT_DIR}/dependencies_check"
 
+export NO_PRERUN_QCOW2="${NO_PRERUN_QCOW2:-1}"
+export USE_QCOW2="${USE_QCOW2:-1}"
+export BASE_QCOW2_SIZE=${BASE_QCOW2_SIZE:-12G}
+source "${SCRIPT_DIR}/qcow2_handling"
+if [ "${USE_QCOW2}" = "1" ]; then
+	NO_PRERUN_QCOW2=1
+else
+	NO_PRERUN_QCOW2=0
+fi
+
+export NO_PRERUN_QCOW2="${NO_PRERUN_QCOW2:-1}"
+
 dependencies_check "${BASE_DIR}/depends"
 
 #check username is valid
@@ -242,22 +295,98 @@ for EXPORT_DIR in ${EXPORT_DIRS}; do
 	# shellcheck source=/dev/null
 	source "${EXPORT_DIR}/EXPORT_IMAGE"
 	EXPORT_ROOTFS_DIR=${WORK_DIR}/$(basename "${EXPORT_DIR}")/rootfs
-	run_stage
+	if [ "${USE_QCOW2}" = "1" ]; then
+		USE_QCOW2=0
+		EXPORT_NAME="${IMG_FILENAME}${IMG_SUFFIX}"
+		echo "------------------------------------------------------------------------"
+		echo "Running export stage for ${EXPORT_NAME}"
+		rm -f "${WORK_DIR}/export-image/${EXPORT_NAME}.img" || true
+		rm -f "${WORK_DIR}/export-image/${EXPORT_NAME}.qcow2" || true
+		rm -f "${WORK_DIR}/${EXPORT_NAME}.img" || true
+		rm -f "${WORK_DIR}/${EXPORT_NAME}.qcow2" || true
+		EXPORT_STAGE=$(basename "${EXPORT_DIR}")
+		for s in $STAGE_LIST; do
+			TMP_LIST=${TMP_LIST:+$TMP_LIST }$(basename "${s}")
+		done
+		FIRST_STAGE=${TMP_LIST%% *}
+		FIRST_IMAGE="image-${FIRST_STAGE}.qcow2"
+
+		pushd "${WORK_DIR}" > /dev/null
+		echo "Creating new base "${EXPORT_NAME}.qcow2" from ${FIRST_IMAGE}"
+		cp "./${FIRST_IMAGE}" "${EXPORT_NAME}.qcow2"
+
+		ARR=($TMP_LIST)
+		# rebase stage images to new export base
+		for CURR_STAGE in "${ARR[@]}"; do
+			if [ "${CURR_STAGE}" = "${FIRST_STAGE}" ]; then
+				PREV_IMG="${EXPORT_NAME}"
+				continue
+			fi
+		echo "Rebasing image-${CURR_STAGE}.qcow2 onto ${PREV_IMG}.qcow2"
+			qemu-img rebase -f qcow2 -u -b ${PREV_IMG}.qcow2 image-${CURR_STAGE}.qcow2
+			if [ "${CURR_STAGE}" = "${EXPORT_STAGE}" ]; then
+				break
+			fi
+			PREV_IMG="image-${CURR_STAGE}"
+		done
+
+		# commit current export stage into base export image
+		echo "Committing image-${EXPORT_STAGE}.qcow2 to ${EXPORT_NAME}.qcow2"
+		qemu-img commit -f qcow2 -p -b "${EXPORT_NAME}.qcow2" image-${EXPORT_STAGE}.qcow2
+
+		# rebase stage images back to original first stage for easy re-run
+		for CURR_STAGE in "${ARR[@]}"; do
+			if [ "${CURR_STAGE}" = "${FIRST_STAGE}" ]; then
+				PREV_IMG="image-${CURR_STAGE}"
+				continue
+			fi
+		echo "Rebasing back image-${CURR_STAGE}.qcow2 onto ${PREV_IMG}.qcow2"
+			qemu-img rebase -f qcow2 -u -b ${PREV_IMG}.qcow2 image-${CURR_STAGE}.qcow2
+			if [ "${CURR_STAGE}" = "${EXPORT_STAGE}" ]; then
+				break
+			fi
+			PREV_IMG="image-${CURR_STAGE}"
+		done
+		popd > /dev/null
+
+		mkdir -p "${WORK_DIR}/export-image/rootfs"
+		mv "${WORK_DIR}/${EXPORT_NAME}.qcow2" "${WORK_DIR}/export-image/"
+		echo "Mounting image ${WORK_DIR}/export-image/${EXPORT_NAME}.qcow2 to rootfs ${WORK_DIR}/export-image/rootfs"
+		mount_qimage "${WORK_DIR}/export-image/${EXPORT_NAME}.qcow2" "${WORK_DIR}/export-image/rootfs"
+
+		CLEAN=0
+		run_stage
+		CLEAN=1
+		USE_QCOW2=1
+
+	else
+		run_stage
+	fi 
 	if [ "${USE_QEMU}" != "1" ]; then
 		if [ -e "${EXPORT_DIR}/EXPORT_NOOBS" ]; then
 			# shellcheck source=/dev/null
 			source "${EXPORT_DIR}/EXPORT_NOOBS"
 			STAGE_DIR="${BASE_DIR}/export-noobs"
-			run_stage
+			if [ "${USE_QCOW2}" = "1" ]; then
+				USE_QCOW2=0
+				run_stage
+				USE_QCOW2=1
+			else
+				run_stage
+			fi
 		fi
 	fi
 done
 
-if [ -x ${BASE_DIR}/postrun.sh ]; then
+if [ -x postrun.sh ]; then
 	log "Begin postrun.sh"
 	cd "${BASE_DIR}"
 	./postrun.sh
 	log "End postrun.sh"
 fi
 
+if [ "${USE_QCOW2}" = "1" ]; then
+	unload_qimage
+fi
+
 log "End ${BASE_DIR}"
diff --git a/depends b/depends
index a86bc82..cb029fd 100644
--- a/depends
+++ b/depends
@@ -17,3 +17,5 @@ file
 git
 lsmod:kmod
 bc
+qemu-nbd:qemu-utils
+kpartx
diff --git a/export-image/03-set-partuuid/00-run.sh b/export-image/03-set-partuuid/00-run.sh
index 1538c07..16e1b15 100755
--- a/export-image/03-set-partuuid/00-run.sh
+++ b/export-image/03-set-partuuid/00-run.sh
@@ -1,13 +1,18 @@
 #!/bin/bash -e
 
-IMG_FILE="${STAGE_WORK_DIR}/${IMG_FILENAME}${IMG_SUFFIX}.img"
+if [ "${NO_PRERUN_QCOW2}" = "0" ]; then
 
-IMGID="$(dd if="${IMG_FILE}" skip=440 bs=1 count=4 2>/dev/null | xxd -e | cut -f 2 -d' ')"
+	IMG_FILE="${STAGE_WORK_DIR}/${IMG_FILENAME}${IMG_SUFFIX}.img"
 
-BOOT_PARTUUID="${IMGID}-01"
-ROOT_PARTUUID="${IMGID}-02"
+	IMGID="$(dd if="${IMG_FILE}" skip=440 bs=1 count=4 2>/dev/null | xxd -e | cut -f 2 -d' ')"
 
-sed -i "s/BOOTDEV/PARTUUID=${BOOT_PARTUUID}/" "${ROOTFS_DIR}/etc/fstab"
-sed -i "s/ROOTDEV/PARTUUID=${ROOT_PARTUUID}/" "${ROOTFS_DIR}/etc/fstab"
+	BOOT_PARTUUID="${IMGID}-01"
+	ROOT_PARTUUID="${IMGID}-02"
+
+	sed -i "s/BOOTDEV/PARTUUID=${BOOT_PARTUUID}/" "${ROOTFS_DIR}/etc/fstab"
+	sed -i "s/ROOTDEV/PARTUUID=${ROOT_PARTUUID}/" "${ROOTFS_DIR}/etc/fstab"
+
+	sed -i "s/ROOTDEV/PARTUUID=${ROOT_PARTUUID}/" "${ROOTFS_DIR}/boot/cmdline.txt"
+
+fi
 
-sed -i "s/ROOTDEV/PARTUUID=${ROOT_PARTUUID}/" "${ROOTFS_DIR}/boot/cmdline.txt"
diff --git a/export-image/04-finalise/01-run.sh b/export-image/04-finalise/01-run.sh
index 0864639..9afa115 100755
--- a/export-image/04-finalise/01-run.sh
+++ b/export-image/04-finalise/01-run.sh
@@ -77,25 +77,30 @@ cp "$ROOTFS_DIR/etc/rpi-issue" "$INFO_FILE"
 	dpkg -l --root "$ROOTFS_DIR"
 } >> "$INFO_FILE"
 
-ROOT_DEV="$(mount | grep "${ROOTFS_DIR} " | cut -f1 -d' ')"
-
-unmount "${ROOTFS_DIR}"
-zerofree "${ROOT_DEV}"
-
-unmount_image "${IMG_FILE}"
-
 mkdir -p "${DEPLOY_DIR}"
 
 rm -f "${DEPLOY_DIR}/${ZIP_FILENAME}${IMG_SUFFIX}.zip"
 rm -f "${DEPLOY_DIR}/${IMG_FILENAME}${IMG_SUFFIX}.img"
 
+mv "$INFO_FILE" "$DEPLOY_DIR/"
+
+if [ "${USE_QCOW2}" = "0" ] && [ "${NO_PRERUN_QCOW2}" = "0" ]; then
+	ROOT_DEV="$(mount | grep "${ROOTFS_DIR} " | cut -f1 -d' ')"
+
+	unmount "${ROOTFS_DIR}"
+	zerofree "${ROOT_DEV}"
+
+	unmount_image "${IMG_FILE}"
+else
+	unload_qimage
+	make_bootable_image "${STAGE_WORK_DIR}/${IMG_FILENAME}${IMG_SUFFIX}.qcow2" "$IMG_FILE"
+fi
+
 if [ "${DEPLOY_ZIP}" == "1" ]; then
 	pushd "${STAGE_WORK_DIR}" > /dev/null
 	zip "${DEPLOY_DIR}/${ZIP_FILENAME}${IMG_SUFFIX}.zip" \
 		"$(basename "${IMG_FILE}")"
 	popd > /dev/null
 else
-	cp "$IMG_FILE" "$DEPLOY_DIR"
+	mv "$IMG_FILE" "$DEPLOY_DIR/"
 fi
-
-cp "$INFO_FILE" "$DEPLOY_DIR"
diff --git a/export-image/prerun.sh b/export-image/prerun.sh
index 8bbc566..efd175a 100755
--- a/export-image/prerun.sh
+++ b/export-image/prerun.sh
@@ -1,61 +1,63 @@
 #!/bin/bash -e
 
-IMG_FILE="${STAGE_WORK_DIR}/${IMG_FILENAME}${IMG_SUFFIX}.img"
+if [ "${NO_PRERUN_QCOW2}" = "0" ]; then
+	IMG_FILE="${STAGE_WORK_DIR}/${IMG_FILENAME}${IMG_SUFFIX}.img"
 
-unmount_image "${IMG_FILE}"
+	unmount_image "${IMG_FILE}"
 
-rm -f "${IMG_FILE}"
+	rm -f "${IMG_FILE}"
 
-rm -rf "${ROOTFS_DIR}"
-mkdir -p "${ROOTFS_DIR}"
+	rm -rf "${ROOTFS_DIR}"
+	mkdir -p "${ROOTFS_DIR}"
 
-BOOT_SIZE="$((256 * 1024 * 1024))"
-ROOT_SIZE=$(du --apparent-size -s "${EXPORT_ROOTFS_DIR}" --exclude var/cache/apt/archives --exclude boot --block-size=1 | cut -f 1)
+	BOOT_SIZE="$((256 * 1024 * 1024))"
+	ROOT_SIZE=$(du --apparent-size -s "${EXPORT_ROOTFS_DIR}" --exclude var/cache/apt/archives --exclude boot --block-size=1 | cut -f 1)
 
-# All partition sizes and starts will be aligned to this size
-ALIGN="$((4 * 1024 * 1024))"
-# Add this much space to the calculated file size. This allows for
-# some overhead (since actual space usage is usually rounded up to the
-# filesystem block size) and gives some free space on the resulting
-# image.
-ROOT_MARGIN="$(echo "($ROOT_SIZE * 0.2 + 200 * 1024 * 1024) / 1" | bc)"
+	# All partition sizes and starts will be aligned to this size
+	ALIGN="$((4 * 1024 * 1024))"
+	# Add this much space to the calculated file size. This allows for
+	# some overhead (since actual space usage is usually rounded up to the
+	# filesystem block size) and gives some free space on the resulting
+	# image.
+	ROOT_MARGIN="$(echo "($ROOT_SIZE * 0.2 + 200 * 1024 * 1024) / 1" | bc)"
 
-BOOT_PART_START=$((ALIGN))
-BOOT_PART_SIZE=$(((BOOT_SIZE + ALIGN - 1) / ALIGN * ALIGN))
-ROOT_PART_START=$((BOOT_PART_START + BOOT_PART_SIZE))
-ROOT_PART_SIZE=$(((ROOT_SIZE + ROOT_MARGIN + ALIGN  - 1) / ALIGN * ALIGN))
-IMG_SIZE=$((BOOT_PART_START + BOOT_PART_SIZE + ROOT_PART_SIZE))
+	BOOT_PART_START=$((ALIGN))
+	BOOT_PART_SIZE=$(((BOOT_SIZE + ALIGN - 1) / ALIGN * ALIGN))
+	ROOT_PART_START=$((BOOT_PART_START + BOOT_PART_SIZE))
+	ROOT_PART_SIZE=$(((ROOT_SIZE + ROOT_MARGIN + ALIGN  - 1) / ALIGN * ALIGN))
+	IMG_SIZE=$((BOOT_PART_START + BOOT_PART_SIZE + ROOT_PART_SIZE))
 
-truncate -s "${IMG_SIZE}" "${IMG_FILE}"
+	truncate -s "${IMG_SIZE}" "${IMG_FILE}"
 
-parted --script "${IMG_FILE}" mklabel msdos
-parted --script "${IMG_FILE}" unit B mkpart primary fat32 "${BOOT_PART_START}" "$((BOOT_PART_START + BOOT_PART_SIZE - 1))"
-parted --script "${IMG_FILE}" unit B mkpart primary ext4 "${ROOT_PART_START}" "$((ROOT_PART_START + ROOT_PART_SIZE - 1))"
+	parted --script "${IMG_FILE}" mklabel msdos
+	parted --script "${IMG_FILE}" unit B mkpart primary fat32 "${BOOT_PART_START}" "$((BOOT_PART_START + BOOT_PART_SIZE - 1))"
+	parted --script "${IMG_FILE}" unit B mkpart primary ext4 "${ROOT_PART_START}" "$((ROOT_PART_START + ROOT_PART_SIZE - 1))"
 
-PARTED_OUT=$(parted -sm "${IMG_FILE}" unit b print)
-BOOT_OFFSET=$(echo "$PARTED_OUT" | grep -e '^1:' | cut -d':' -f 2 | tr -d B)
-BOOT_LENGTH=$(echo "$PARTED_OUT" | grep -e '^1:' | cut -d':' -f 4 | tr -d B)
+	PARTED_OUT=$(parted -sm "${IMG_FILE}" unit b print)
+	BOOT_OFFSET=$(echo "$PARTED_OUT" | grep -e '^1:' | cut -d':' -f 2 | tr -d B)
+	BOOT_LENGTH=$(echo "$PARTED_OUT" | grep -e '^1:' | cut -d':' -f 4 | tr -d B)
 
-ROOT_OFFSET=$(echo "$PARTED_OUT" | grep -e '^2:' | cut -d':' -f 2 | tr -d B)
-ROOT_LENGTH=$(echo "$PARTED_OUT" | grep -e '^2:' | cut -d':' -f 4 | tr -d B)
+	ROOT_OFFSET=$(echo "$PARTED_OUT" | grep -e '^2:' | cut -d':' -f 2 | tr -d B)
+	ROOT_LENGTH=$(echo "$PARTED_OUT" | grep -e '^2:' | cut -d':' -f 4 | tr -d B)
 
-BOOT_DEV=$(losetup --show -f -o "${BOOT_OFFSET}" --sizelimit "${BOOT_LENGTH}" "${IMG_FILE}")
-ROOT_DEV=$(losetup --show -f -o "${ROOT_OFFSET}" --sizelimit "${ROOT_LENGTH}" "${IMG_FILE}")
-echo "/boot: offset $BOOT_OFFSET, length $BOOT_LENGTH"
-echo "/:     offset $ROOT_OFFSET, length $ROOT_LENGTH"
+	BOOT_DEV=$(losetup --show -f -o "${BOOT_OFFSET}" --sizelimit "${BOOT_LENGTH}" "${IMG_FILE}")
+	ROOT_DEV=$(losetup --show -f -o "${ROOT_OFFSET}" --sizelimit "${ROOT_LENGTH}" "${IMG_FILE}")
+	echo "/boot: offset $BOOT_OFFSET, length $BOOT_LENGTH"
+	echo "/:     offset $ROOT_OFFSET, length $ROOT_LENGTH"
 
-ROOT_FEATURES="^huge_file"
-for FEATURE in metadata_csum 64bit; do
+	ROOT_FEATURES="^huge_file"
+	for FEATURE in metadata_csum 64bit; do
 	if grep -q "$FEATURE" /etc/mke2fs.conf; then
-	    ROOT_FEATURES="^$FEATURE,$ROOT_FEATURES"
+		ROOT_FEATURES="^$FEATURE,$ROOT_FEATURES"
 	fi
-done
-mkdosfs -n boot -F 32 -v "$BOOT_DEV" > /dev/null
-mkfs.ext4 -L rootfs -O "$ROOT_FEATURES" "$ROOT_DEV" > /dev/null
+	done
+	mkdosfs -n boot -F 32 -v "$BOOT_DEV" > /dev/null
+	mkfs.ext4 -L rootfs -O "$ROOT_FEATURES" "$ROOT_DEV" > /dev/null
 
-mount -v "$ROOT_DEV" "${ROOTFS_DIR}" -t ext4
-mkdir -p "${ROOTFS_DIR}/boot"
-mount -v "$BOOT_DEV" "${ROOTFS_DIR}/boot" -t vfat
+	mount -v "$ROOT_DEV" "${ROOTFS_DIR}" -t ext4
+	mkdir -p "${ROOTFS_DIR}/boot"
+	mount -v "$BOOT_DEV" "${ROOTFS_DIR}/boot" -t vfat
 
-rsync -aHAXx --exclude /var/cache/apt/archives --exclude /boot "${EXPORT_ROOTFS_DIR}/" "${ROOTFS_DIR}/"
-rsync -rtx "${EXPORT_ROOTFS_DIR}/boot/" "${ROOTFS_DIR}/boot/"
+	rsync -aHAXx --exclude /var/cache/apt/archives --exclude /boot "${EXPORT_ROOTFS_DIR}/" "${ROOTFS_DIR}/"
+	rsync -rtx "${EXPORT_ROOTFS_DIR}/boot/" "${ROOTFS_DIR}/boot/"
+fi
diff --git a/export-noobs/00-release/00-run.sh b/export-noobs/00-release/00-run.sh
index 18a3a5d..216096b 100755
--- a/export-noobs/00-release/00-run.sh
+++ b/export-noobs/00-release/00-run.sh
@@ -40,4 +40,8 @@ sed "${NOOBS_DIR}/os.json" -i -e "s|RELEASE|${RELEASE}|"
 
 sed "${NOOBS_DIR}/release_notes.txt" -i -e "s|UNRELEASED|${IMG_DATE}|"
 
-cp -a "${NOOBS_DIR}" "${DEPLOY_DIR}/"
+if [ "${USE_QCOW2}" = "1" ]; then
+	mv "${NOOBS_DIR}" "${DEPLOY_DIR}/"
+else
+	cp -a "${NOOBS_DIR}" "${DEPLOY_DIR}/"
+fi
diff --git a/export-noobs/prerun.sh b/export-noobs/prerun.sh
index 54e0c59..b7f2b4a 100755
--- a/export-noobs/prerun.sh
+++ b/export-noobs/prerun.sh
@@ -1,11 +1,15 @@
 #!/bin/bash -e
 
-IMG_FILE="${STAGE_WORK_DIR}/${IMG_FILENAME}${IMG_SUFFIX}.img"
 NOOBS_DIR="${STAGE_WORK_DIR}/${IMG_DATE}-${IMG_NAME}${IMG_SUFFIX}"
-unmount_image "${IMG_FILE}"
-
 mkdir -p "${STAGE_WORK_DIR}"
-cp "${WORK_DIR}/export-image/${IMG_FILENAME}${IMG_SUFFIX}.img" "${STAGE_WORK_DIR}/"
+
+if [ "${DEPLOY_ZIP}" == "1" ]; then
+	IMG_FILE="${WORK_DIR}/export-image/${IMG_FILENAME}${IMG_SUFFIX}.img"
+else
+	IMG_FILE="${DEPLOY_DIR}/${IMG_FILENAME}${IMG_SUFFIX}.img"
+fi
+
+unmount_image "${IMG_FILE}"
 
 rm -rf "${NOOBS_DIR}"
 
@@ -33,4 +37,8 @@ bsdtar --numeric-owner --format gnutar -C "${STAGE_WORK_DIR}/rootfs/boot" -cpf -
 umount "${STAGE_WORK_DIR}/rootfs/boot"
 bsdtar --numeric-owner --format gnutar -C "${STAGE_WORK_DIR}/rootfs" --one-file-system -cpf - . | xz -T0 > "${NOOBS_DIR}/root.tar.xz"
 
+if [ "${USE_QCOW2}" = "1" ]; then
+	rm "$ROOTFS_DIR/etc/systemd/system/multi-user.target.wants/apply_noobs_os_config.service"
+fi
+
 unmount_image "${IMG_FILE}"
diff --git a/imagetool.sh b/imagetool.sh
new file mode 100755
index 0000000..adc1ab7
--- /dev/null
+++ b/imagetool.sh
@@ -0,0 +1,112 @@
+#!/bin/bash
+
+if [ "$(id -u)" != "0" ]; then
+		echo "Please run as root" 1>&2
+		exit 1
+fi
+
+progname=$(basename $0)
+
+function usage()
+{
+	cat << HEREDOC
+
+Usage:
+    Mount Image : $progname [--mount] [--image-name <path to qcow2 image>] [--mount-point <mount point>]
+    Umount Image: $progname [--umount] [--mount-point <mount point>]
+    Cleanup NBD : $progname [--cleanup]
+
+   arguments:
+     -h, --help           show this help message and exit
+     -c, --cleanup        cleanup orphaned device mappings
+     -m, --mount          mount image
+     -u, --umount         umount image
+     -i, --image-name     path to qcow2 image
+     -p, --mount-point    mount point for image
+
+   This tool will use /dev/nbd1 as default for mounting an image. If you want to use another device, execute like this:
+   NBD_DEV=/dev/nbd2 ./$progname --mount --image <your image> --mount-point <your path>
+
+HEREDOC
+}
+
+MOUNT=0
+UMOUNT=0
+IMAGE=""
+MOUNTPOINT=""
+
+nbd_cleanup() {
+	DEVS="$(lsblk | grep nbd | grep disk | cut -d" " -f1)"
+	if [ ! -z "${DEVS}" ]; then
+		for d in $DEVS; do
+			if [ ! -z "${d}" ]; then
+				QDEV="$(ps xa | grep $d | grep -v grep)"
+				if [ -z "${QDEV}" ]; then
+					kpartx -d /dev/$d && echo "Unconnected device map removed: /dev/$d"
+				fi
+			fi
+		done
+	fi
+}
+
+# As long as there is at least one more argument, keep looping
+while [[ $# -gt 0 ]]; do
+	key="$1"
+	case "$key" in
+		-h|--help)
+			usage
+		exit
+		;;
+		-c|--cleanup)
+			nbd_cleanup
+		;;
+		-m|--mount)
+			MOUNT=1
+		;;
+		-u|--umount)
+			UMOUNT=1
+		;;
+		-i|--image-name)
+			shift
+			IMAGE="$1"
+		;;
+		-p|--mount-point)
+			shift
+			MOUNTPOINT="$1"
+		;;
+		*)
+			echo "Unknown option '$key'"
+			usage
+			exit
+		;;
+	esac
+	# Shift after checking all the cases to get the next option
+	shift
+done
+
+if [ "${MOUNT}" = "1" ] && [ "${UMOUNT}" = "1" ]; then
+	usage
+	echo "Concurrent mount options not possible."
+	exit
+fi
+
+if [ "${MOUNT}" = "1" ] && ([ -z "${IMAGE}"  ] || [ -z "${MOUNTPOINT}"  ]); then
+	usage
+	echo "Can not mount image. Image path and/or mount point missing."
+	exit
+fi
+
+if [ "${UMOUNT}" = "1" ] && [ -z "${MOUNTPOINT}" ]; then
+	usage
+	echo "Can not umount. Mount point parameter missing."
+	exit
+fi
+
+export NBD_DEV="${NBD_DEV:-/dev/nbd1}"
+source scripts/qcow2_handling
+
+if [ "${MOUNT}" = "1" ]; then
+	mount_qimage "${MOUNTPOINT}" "${IMAGE}"
+elif [ "${UMOUNT}" = "1" ]; then
+	umount_qimage "${MOUNTPOINT}"
+fi
diff --git a/scripts/qcow2_handling b/scripts/qcow2_handling
new file mode 100644
index 0000000..f722937
--- /dev/null
+++ b/scripts/qcow2_handling
@@ -0,0 +1,256 @@
+#!/bin/bash
+
+# QCOW2 Routines
+
+export CURRENT_IMAGE
+export CURRENT_MOUNTPOINT
+
+export NBD_DEV
+export MAP_BOOT_DEV
+export MAP_ROOT_DEV
+
+# set in build.sh
+# should be fairly enough for the beginning
+# overwrite here by uncommenting following lines
+# BASE_QCOW2_SIZE=12G
+
+# find and initialize free block device nodes
+init_nbd() {
+	modprobe nbd max_part=16
+	if [ -z "${NBD_DEV}" ]; then
+	for x in /sys/class/block/nbd* ; do
+		S=`cat $x/size`
+		if [ "$S" == "0" ] ; then
+			NBD_DEV=/dev/$(basename $x)
+			MAP_BOOT_DEV=/dev/mapper/$(basename $x)p1
+			MAP_ROOT_DEV=/dev/mapper/$(basename $x)p2
+			break
+		fi
+	done
+	fi
+}
+export -f init_nbd
+
+# connect image to block device
+connect_blkdev() {
+	init_nbd
+	qemu-nbd --discard=unmap -c $NBD_DEV "$1"
+	sync
+	kpartx -a $NBD_DEV
+	sync
+	CURRENT_IMAGE="$1"
+}
+export -f connect_blkdev
+
+# disconnect image from block device
+disconnect_blkdev() {
+	kpartx -d $NBD_DEV
+	qemu-nbd -d $NBD_DEV
+	NBD_DEV=
+	MAP_BOOT_DEV=
+	MAP_ROOT_DEV=
+	CURRENT_IMAGE=
+}
+export -f disconnect_blkdev
+
+# mount qcow2 image: mount_image <image file> <mountpoint>
+mount_qimage() {
+	connect_blkdev "$1"
+	mount -v -t ext4 $MAP_ROOT_DEV "$2"
+	mkdir -p "${ROOTFS_DIR}/boot"
+	mount -v -t vfat $MAP_BOOT_DEV "$2/boot"
+	CURRENT_MOUNTPOINT="$2"
+}
+export -f mount_qimage
+
+# umount qcow2 image: umount_image <current mountpoint>
+umount_qimage() {
+	sync
+	#umount "$1/boot"
+	while mount | grep -q "$1"; do
+		local LOCS
+		LOCS=$(mount | grep "$1" | cut -f 3 -d ' ' | sort -r)
+		for loc in $LOCS; do
+			echo "$loc"
+			while mountpoint -q "$loc" && ! umount "$loc"; do
+				sleep 0.1
+			done
+		done
+	done
+	CURRENT_MOUNTPOINT=
+	disconnect_blkdev
+}
+export -f umount_qimage
+
+# create base image / backing image / mount image
+load_qimage() {
+	if [ -z "${CURRENT_MOUNTPOINT}" ]; then
+		if [ ! -d "${ROOTFS_DIR}" ]; then
+			mkdir -p "${ROOTFS_DIR}";
+		fi
+
+		if [ "${CLEAN}" = "1" ] && [ -f "${WORK_DIR}/image-${STAGE}.qcow2" ]; then
+			rm -f "${WORK_DIR}/image-${STAGE}.qcow2";
+		fi
+
+		if [ ! -f "${WORK_DIR}/image-${STAGE}.qcow2" ]; then
+			pushd ${WORK_DIR} > /dev/null
+			init_nbd
+			if [ -z "${PREV_STAGE}" ]; then
+				echo "Creating base image: image-${STAGE}.qcow2"
+				#  -o preallocation=falloc
+				qemu-img create -f qcow2 image-${STAGE}.qcow2 $BASE_QCOW2_SIZE
+				sync
+				qemu-nbd --discard=unmap -c $NBD_DEV image-${STAGE}.qcow2
+				sync
+				sfdisk $NBD_DEV << EOF
+4MiB,250MiB,c,*
+254MiB,,83;
+EOF
+				sync
+				kpartx -a $NBD_DEV
+				mkdosfs -n boot -F 32 -v $MAP_BOOT_DEV
+				mkfs.ext4 -L rootfs -O "^huge_file,^metadata_csum,^64bit" $MAP_ROOT_DEV
+				sync
+			else
+				if [ ! -f "${WORK_DIR}/image-${PREV_STAGE}.qcow2" ]; then
+					exit 1;
+				fi
+				echo "Creating backing image: image-${STAGE}.qcow2 <- ${WORK_DIR}/image-${PREV_STAGE}.qcow2"
+				qemu-img create -f qcow2 \
+					-o backing_file=${WORK_DIR}/image-${PREV_STAGE}.qcow2 \
+					${WORK_DIR}/image-${STAGE}.qcow2
+				sync
+				qemu-nbd --discard=unmap -c $NBD_DEV image-${STAGE}.qcow2
+				sync
+				kpartx -a $NBD_DEV
+			fi
+
+			mount -v -t ext4 $MAP_ROOT_DEV "${ROOTFS_DIR}"
+			mkdir -p "${ROOTFS_DIR}/boot"
+			mount -v -t vfat $MAP_BOOT_DEV "${ROOTFS_DIR}/boot"
+			CURRENT_IMAGE=${WORK_DIR}/image-${STAGE}.qcow2
+			CURRENT_MOUNTPOINT=${ROOTFS_DIR}
+			popd > /dev/null
+		else
+			mount_qimage "${WORK_DIR}/image-${STAGE}.qcow2" "${ROOTFS_DIR}"
+		fi
+		echo "Current image in use: ${CURRENT_IMAGE} (MP: ${CURRENT_MOUNTPOINT})"
+	fi
+}
+export -f load_qimage
+
+# umount current image and refresh mount point env var
+unload_qimage() {
+	if [ ! -z "${CURRENT_MOUNTPOINT}" ]; then
+		fstrim -v "${CURRENT_MOUNTPOINT}" || true
+		umount_qimage "${CURRENT_MOUNTPOINT}"
+	fi
+}
+export -f unload_qimage
+
+# based on: https://github.com/SirLagz/RaspberryPi-ImgAutoSizer
+# helper function for make_bootable_image, do not call directly
+function resize_qcow2() {
+	if [ -z "$CALL_FROM_MBI" ]; then
+		echo "resize_qcow2: cannot be called directly, use make_bootable_image instead"
+		return 1
+	fi
+
+	# ROOT_MARGIN=$((800*1024*1024))
+	ROOT_MARGIN=$((1*1024*1024))
+	PARTED_OUT=`parted -s -m "$NBD_DEV" unit B print`
+	PART_NO=`echo "$PARTED_OUT" | grep ext4 | awk -F: ' { print $1 } '`
+	PART_START=`echo "$PARTED_OUT" | grep ext4 | awk -F: ' { print substr($2,1,length($2)-1) } '`
+
+	e2fsck -y -f $MAP_ROOT_DEV || true
+
+	DATA_SIZE=`resize2fs -P $MAP_ROOT_DEV | awk -F': ' ' { print $2 } '`
+	BLOCK_SIZE=$(dumpe2fs -h $MAP_ROOT_DEV | grep 'Block size' | awk -F': ' ' { print $2 }')
+	BLOCK_SIZE=${BLOCK_SIZE// /}
+
+	let DATA_SIZE=$DATA_SIZE+$ROOT_MARGIN/$BLOCK_SIZE
+	resize2fs -p $MAP_ROOT_DEV $DATA_SIZE
+	sleep 1
+
+	let PART_NEW_SIZE=$DATA_SIZE*$BLOCK_SIZE
+	let PART_NEW_END=$PART_START+$PART_NEW_SIZE
+	ACT1=`parted -s "$NBD_DEV" rm 2`
+	ACT2=`parted -s "$NBD_DEV" unit B mkpart primary $PART_START $PART_NEW_END`
+	NEW_IMG_SIZE=`parted -s -m "$NBD_DEV" unit B print free | tail -1 | awk -F: ' { print substr($2,1,length($2)-1) } '`
+}
+export -f resize_qcow2
+
+# create raw img from qcow2: make_bootable_image <in.qcow2> <out.img>
+function make_bootable_image() {
+    
+	EXPORT_QCOW2="$1"
+	EXPORT_IMAGE="$2"
+
+	echo "Connect block device to source qcow2"
+	connect_blkdev "${EXPORT_QCOW2}"
+
+	echo "Resize fs and partition"
+	CALL_FROM_MBI=1
+	resize_qcow2
+	sync
+	CALL_FROM_MBI=
+
+	echo "Disconnect block device"
+	disconnect_blkdev
+
+	if [ -z "$NEW_IMG_SIZE" ]; then
+		echo "NEW_IMG_SIZE could not be calculated, cannot process image. Exit."
+		exit 1
+	fi
+
+	echo "Shrinking qcow2 image"
+	qemu-img resize --shrink "${EXPORT_QCOW2}" $NEW_IMG_SIZE
+	sync
+
+	echo "Convert qcow2 to raw image"
+	qemu-img convert -f qcow2 -O raw "${EXPORT_QCOW2}" "${EXPORT_IMAGE}"
+	sync
+
+	echo "Get PARTUUIDs from image"
+	IMGID="$(blkid -o value -s PTUUID "${EXPORT_IMAGE}")"
+
+	BOOT_PARTUUID="${IMGID}-01"
+	echo "Boot: $BOOT_PARTUUID"
+	ROOT_PARTUUID="${IMGID}-02"
+	echo "Root: $ROOT_PARTUUID"
+
+	echo "Mount image"
+	MOUNTROOT=${WORK_DIR}/tmpimage
+	mkdir -p $MOUNTROOT
+
+	MOUNTPT=$MOUNTROOT
+	PARTITION=2
+	mount "${EXPORT_IMAGE}" "$MOUNTPT" -o loop,offset=$[ `/sbin/sfdisk -d "${EXPORT_IMAGE}" | grep "start=" | head -n $PARTITION | tail -n1 | sed 's/.*start=[ ]*//' | sed 's/,.*//'` * 512 ],sizelimit=$[ `/sbin/sfdisk -d "${EXPORT_IMAGE}" | grep "start=" | head -n $PARTITION | tail -n1 | sed 's/.*size=[ ]*//' | sed 's/,.*//'` * 512 ] || exit 1
+
+	MOUNTPT=$MOUNTROOT/boot
+	PARTITION=1
+	mount "${EXPORT_IMAGE}" "$MOUNTPT" -o loop,offset=$[ `/sbin/sfdisk -d "${EXPORT_IMAGE}" | grep "start=" | head -n $PARTITION | tail -n1 | sed 's/.*start=[ ]*//' | sed 's/,.*//'` * 512 ],sizelimit=$[ `/sbin/sfdisk -d "${EXPORT_IMAGE}" | grep "start=" | head -n $PARTITION | tail -n1 | sed 's/.*size=[ ]*//' | sed 's/,.*//'` * 512 ] || exit 1
+
+	if [ ! -d "${MOUNTROOT}/root" ]; then
+		echo "Image damaged or not mounted. Exit."
+		exit 1
+	fi
+
+	echo "Setup PARTUUIDs"
+	if [ ! -z "$BOOT_PARTUUID" ] && [ ! -z "$ROOT_PARTUUID" ]; then
+		echo "Set UUIDs to make it bootable"
+		sed -i "s/BOOTDEV/PARTUUID=${BOOT_PARTUUID}/" "${MOUNTROOT}/etc/fstab"
+		sed -i "s/ROOTDEV/PARTUUID=${ROOT_PARTUUID}/" "${MOUNTROOT}/etc/fstab"
+		sed -i "s/ROOTDEV/PARTUUID=${ROOT_PARTUUID}/" "${MOUNTROOT}/boot/cmdline.txt"
+	fi
+
+	echo "Umount image"
+	sync
+	umount "${MOUNTROOT}/boot" || exit 1
+	umount "${MOUNTROOT}" || exit 1
+
+	echo "Remove qcow2 export image"
+	rm -f "${EXPORT_QCOW2}"
+}
+export -f make_bootable_image
diff --git a/stage0/prerun.sh b/stage0/prerun.sh
index 3b25783..d4dd0a1 100755
--- a/stage0/prerun.sh
+++ b/stage0/prerun.sh
@@ -1,5 +1,5 @@
 #!/bin/bash -e
 
-if [ ! -d "${ROOTFS_DIR}" ]; then
+if [ ! -d "${ROOTFS_DIR}" ] || [ "${USE_QCOW2}" = "1" ]; then
 	bootstrap ${RELEASE} "${ROOTFS_DIR}" http://raspbian.raspberrypi.org/raspbian/
 fi