diff --git a/opennebula-images/freebsd-build-opennebula-image.sh b/opennebula-images/freebsd-build-opennebula-image.sh
index af5e6a8..4c4d841 100755
--- a/opennebula-images/freebsd-build-opennebula-image.sh
+++ b/opennebula-images/freebsd-build-opennebula-image.sh
@@ -2,25 +2,43 @@
 
 # This script generates FreeBSD images for OpenNebula, being heavily inspired
 # from srht's FreeBSD build image definition. It assumes running on a FreeBSD host.
+# ZFS installation as documented by the FreeBSD project
+# https://wiki.freebsd.org/RootOnZFS/GPTZFSBoot
 
 set -e
 set -x
 
 # XXX: Handle command-line arguments?
-RELEASE=13.0-RELEASE
+RELEASE=13.1-RELEASE
 ARCH=amd64
-IMAGE_PATH=freebsd-$RELEASE-$(date -I).img.qcow2
+IMAGE_PATH_ZFS=freebsd-zfs-$RELEASE-$(date -I).img.qcow2
+IMAGE_PATH_UFS=freebsd-ufs-$RELEASE-$(date -I).img.qcow2
 IMAGE_SIZE=10G
 
 DIST_BASE="https://download.freebsd.org/ftp/releases/$ARCH/$RELEASE"
+CLSETUP_COMMIT=82d7d16ff14e1893f06f39788bb7cd8604284583
+CLSETUP_URL="https://git.sr.ht/~jornane/clsetup/archive/$CLSETUP_COMMIT.tar.gz"
+ZPOOL=zroot
 
-ONE_CONTEXT_PKG_URL="https://github.com/OpenNebula/addon-context-linux/releases/download/v6.2.0/one-context-6.2.0_1.txz"
+ZFSTARGET="$(mktemp -d /var/tmp/zfsbuild.XXXXX)"
+UFSTARGET="$(mktemp -d /var/tmp/ufsbuild.XXXXX)"
+CLSETUP_WORK="$(mktemp -d /var/tmp/clsetup.XXXXX)"
+
+if zpool list -Ho name $ZPOOL 2>/dev/null; then
+	echo "The pool $ZPOOL is already imported." >&2
+	exit 1
+fi
 
 cleanup() {
-	sync || true
-	umount /mnt/dev || true
-	umount /mnt || true
-	mdconfig -du md0 || true
+	sync ||:
+	umount "$UFSTARGET/dev" ||:
+	umount "$UFSTARGET/tmp" ||:
+	umount "$UFSTARGET/var/tmp" ||:
+	umount "$UFSTARGET" ||:
+	zpool export $ZPOOL ||:
+	mdconfig -du md0 ||:
+	mdconfig -du md1 ||:
+	rm -rf "$CLSETUP_WORK"
 }
 trap cleanup EXIT
 
@@ -29,82 +47,144 @@ if [ "$(whoami)" != 'root' ]; then
 	exit 1
 fi
 
-env ASSUME_ALWAYS_YES=YES pkg install -y qemu-tools
+if ! command -v rsync >/dev/null
+then
+	env ASSUME_ALWAYS_YES=YES pkg install -y rsync
+fi
+if ! command -v qemu-img >/dev/null
+then
+	env ASSUME_ALWAYS_YES=YES pkg install -y qemu-tools
+fi
 
-# Allocate and partition/format disk image.
-disk=$(mktemp)
-truncate -s 6G $disk
-mdconfig -a -t vnode -f $disk -u md0
-gpart create -s gpt /dev/md0
-gpart add -t freebsd-boot -l bootfs -b 40 -s 512K md0
-gpart bootcode -b /boot/pmbr -p /boot/gptboot -i 1 md0
-gpart add -t freebsd-ufs -l rootfs -b 1M -s 5G md0
-newfs -U /dev/md0p2
+fetch -qo- "$CLSETUP_URL" | tar -C "$CLSETUP_WORK" --strip-components 1 -xzf-
+
+ufsdisk=$(mktemp /var/tmp/ufsdisk.XXXXX)
+truncate -s 6G $ufsdisk
+mdconfig -a -t vnode -f $ufsdisk -u md1
+gpart create -s gpt /dev/md1
+gpart add -t freebsd-boot -l bootfs -b 40 -s 512K md1
+gpart bootcode -b /boot/pmbr -p /boot/gptboot -i 1 md1
+gpart add -t freebsd-ufs -l rootfs -b 1M -s 5G md1
+newfs -U /dev/md1p2
 
 # Mount allocated image.
-mount /dev/md0p2 /mnt
-mkdir -p /mnt/dev
-mount -t devfs devfs /mnt/dev
+mount /dev/md1p2 "$UFSTARGET"
+
+# Allocate and partition/format disk image.
+# We use "legacy boot", aka BIOS boot
+# Preferably, we'd use EFI boot here, check the FreeBSD wiki link in the header
+# to see how to make that change, but make the EFI partition larger
+zfsdisk=$(mktemp /var/tmp/zfsdisk.XXXXX)
+truncate -s 6G $zfsdisk
+mdconfig -a -t vnode -f $zfsdisk -u md0
+gpart create -s gpt /dev/md0
+gpart add -t freebsd-boot -l bootfs -b 40 -s 512K md0
+gpart bootcode -b /boot/pmbr -p /boot/gptzfsboot -i 1 md0
+gpart add -t freebsd-zfs -l zfs0 -b 1M -s 5G md0
+zpool create -O compression=on -o ashift=12 -o altroot="$ZFSTARGET" -m none $ZPOOL md0p2
+
+zfs create -o mountpoint=none                                  $ZPOOL/ROOT
+# We set zstd-19 so our image will become smaller, at the cost of a longer build time.
+# At the end of the process, we disable zstd-19 again using zfs inherit compression,
+# but all files already written will remain zstd-19 compressed
+zfs create -o mountpoint=/ -o canmount=noauto                  $ZPOOL/ROOT/default
+mount -t zfs $ZPOOL/ROOT/default "$ZFSTARGET"
+zpool set bootfs=$ZPOOL/ROOT/default $ZPOOL
+
+zfs create -o mountpoint=/tmp  -o exec=on      -o setuid=off   $ZPOOL/tmp
+zfs create -o canmount=off -o mountpoint=/usr                  $ZPOOL/usr
+zfs create                                                     $ZPOOL/usr/home
+zfs create                     -o exec=off     -o setuid=off   $ZPOOL/usr/src
+zfs create -o mountpoint=/usr/ports            -o setuid=off   $ZPOOL/usr/ports
+zfs create -o canmount=off -o mountpoint=/var                  $ZPOOL/var
+zfs create                     -o exec=off     -o setuid=off   $ZPOOL/var/audit
+zfs create                     -o exec=off     -o setuid=off   $ZPOOL/var/crash
+zfs create                     -o exec=off     -o setuid=off   $ZPOOL/var/log
+zfs create -o atime=on         -o exec=off     -o setuid=off   $ZPOOL/var/mail
+zfs create                     -o exec=on      -o setuid=off   $ZPOOL/var/tmp
+
+ln -s /usr/home "$ZFSTARGET/home"
+chmod 1777 "$ZFSTARGET/var/tmp"
+chmod 1777 "$ZFSTARGET/tmp"
+
+# Mount dev in chroot
+mkdir -p "$UFSTARGET/dev"
+mount -t devfs devfs "$UFSTARGET/dev"
 
 # Download and extract base system.
 dist_files="kernel.txz base.txz"
 dist_dir="/usr/freebsd-dist/$ARCH/$RELEASE"
 
-mkdir -p "$dist_dir"
+mkdir -p "$dist_dir" "$UFSTARGET"
 for f in $dist_files
 do
 	fetch -m -o "$dist_dir/$f" "$DIST_BASE/$f"
-	tar -C /mnt -xJf "$dist_dir/$f"
+	tar -C "$UFSTARGET" -xJf "$dist_dir/$f"
 done
 
+# Avoid writing temporary files while building
+mount_nullfs /tmp "$UFSTARGET/tmp"
+mount_nullfs /var/tmp "$UFSTARGET/var/tmp"
+
+# Install the first-boot script that configures the network and ssh key
+make -C "$CLSETUP_WORK/" PREFIX="$UFSTARGET/usr/local" install
+
 # Configure new system.
-echo "/dev/gpt/rootfs / ufs rw,noatime 1 1" >/mnt/etc/fstab
-touch /mnt/firstboot
-sysrc -f /mnt/boot/loader.conf autoboot_delay=-1
+printf '# Device\tMountpoint\tFStype\tOptions\t\tDump\tPass#\n' >"$UFSTARGET/etc/fstab"
+touch "$UFSTARGET/firstboot"
+sysrc -f "$UFSTARGET/boot/loader.conf" \
+	zfs_load=YES \
+	autoboot_delay=-1 \
 
-sysrc -f /mnt/etc/rc.conf ntpd_enable=YES sshd_enable=YES growfs_enable=YES hostname=freebsd
+sysrc -f "$UFSTARGET/etc/rc.conf" \
+	ntpd_enable=YES \
+	sshd_enable=YES \
+	growfs_enable=YES \
+	hostname=freebsd \
+	firstboot_clsetup_enable=YES \
 
-cp /etc/resolv.conf /mnt/etc/resolv.conf
-tzsetup -s -C /mnt UTC
+# The resolv.conf file is written by firstboot_clsetup
+#cp /etc/resolv.conf "$UFSTARGET/etc/resolv.conf"
 
-cat >>/mnt/etc/ssh/sshd_config <<EOF
+tzsetup -s -C "$UFSTARGET" UTC
+
+cat >>"$UFSTARGET/etc/ssh/sshd_config" <<EOF
 PermitRootLogin yes
 PasswordAuthentication no
 PermitEmptyPasswords no
 EOF
 
-# It doesn't appear to be necessary to use "latest", "quarterly" is new enough
-#mkdir -p /mnt/usr/local/etc/pkg/repos/
-#sed -es@quarterly@latest@ </mnt/etc/pkg/FreeBSD.conf >/mnt/usr/local/etc/pkg/repos/FreeBSD.conf
-
 # freebsd-update is only supported for RELEASE
-if [ "${release%-RELEASE}" != "$RELEASE" ]
+if printf %s "$RELEASE" | grep -q '.-RELEASE$'
 then
 	env PAGER=true /usr/sbin/freebsd-update \
-		-b /mnt \
+		-b "$UFSTARGET" \
 		--currently-running "$RELEASE" \
 		--not-running-from-cron -F \
 		fetch install
-	rm -rf /mnt/var/db/freebsd-update/*
 fi
+rm -rf "$UFSTARGET/var/db/freebsd-update/"* ||:
 
-env ASSUME_ALWAYS_YES=YES pkg -c /mnt bootstrap -f
-
-fetch -m -o /mnt/one-context.txz "$ONE_CONTEXT_PKG_URL"
-# OpenNebula has dependencies, but these are not included in the package for some reason
-# https://github.com/OpenNebula/addon-context-linux/blob/40efc929487b2955e6f32643853a5cdc93c548da/targets.sh#L25
-# It would be useful to see if there is an alternative to OpenNebula without so many dependencies,
-# so we can run on FreeBSD base, and avoid breaking OpenNebula when the admin removes a dependency.
-env ASSUME_ALWAYS_YES=YES pkg -c /mnt install sudo bash curl base64 ruby open-vm-tools-nox11 gawk virt-what one-context.txz
-env ASSUME_ALWAYS_YES=YES pkg -c /mnt clean --all
-rm /mnt/one-context.txz
+# Set zstd-19 compression, copy all data to the pool, and then set compression to default again
+# This will make the base image smaller, at the cost of taking longer to generate, as zstd-19 is slow to write
+# Therefore, afterwards we restore compression to default, so written files stay zstd-19, which is fast to read,
+# but files written by the user afterwards will be written with the default compression algorihtm.
+zfs set compression=zstd-19 $ZPOOL/ROOT/default
+umount "$UFSTARGET/dev" "$UFSTARGET/tmp" "$UFSTARGET/var/tmp"
+rsync -aH --fileflags --inplace "$UFSTARGET/." "$ZFSTARGET"
+sysrc -f "$UFSTARGET/boot/loader.conf" -x zfs_load
+printf '%s\t%s\t\t%s\t%s\t%s\t%s\n' /dev/gpt/rootfs / ufs rw,noatime 1 1 >>"$UFSTARGET/etc/fstab"
+sync ||:
+zfs inherit compression $ZPOOL/ROOT/default
 
 trap : EXIT
 cleanup
 
 mkdir -p "$ARCH"
-qemu-img convert -f raw -O qcow2 "$disk" "$IMAGE_PATH"
-rm "$disk"
+qemu-img convert -f raw -O qcow2 "$zfsdisk" "$ARCH/$IMAGE_PATH_ZFS"
+qemu-img convert -f raw -O qcow2 "$ufsdisk" "$ARCH/$IMAGE_PATH_UFS"
+rm "$zfsdisk" "$ufsdisk"
 
 # Filesystem will be enlarged by growfs(7) on next startup
-qemu-img resize "$IMAGE_PATH" "$IMAGE_SIZE"
+qemu-img resize "$ARCH/$IMAGE_PATH_ZFS" "$IMAGE_SIZE"
+qemu-img resize "$ARCH/$IMAGE_PATH_UFS" "$IMAGE_SIZE"
diff --git a/opennebula-images/freebsd-zfs-build-opennebula-image.sh b/opennebula-images/freebsd-zfs-build-opennebula-image.sh
deleted file mode 100755
index 39992ce..0000000
--- a/opennebula-images/freebsd-zfs-build-opennebula-image.sh
+++ /dev/null
@@ -1,148 +0,0 @@
-#!/bin/sh
-
-# This script generates FreeBSD images for OpenNebula, being heavily inspired
-# from srht's FreeBSD build image definition. It assumes running on a FreeBSD host.
-# ZFS installation as documented by the FreeBSD project
-# https://wiki.freebsd.org/RootOnZFS/GPTZFSBoot
-
-set -e
-set -x
-
-# XXX: Handle command-line arguments?
-RELEASE=13.0-RELEASE
-ARCH=amd64
-IMAGE_PATH=freebsd-zfs-$RELEASE-$(date -I).img.qcow2
-IMAGE_SIZE=10G
-
-DIST_BASE="https://download.freebsd.org/ftp/releases/$ARCH/$RELEASE"
-ZPOOL=zroot
-
-ONE_CONTEXT_PKG_URL="https://github.com/OpenNebula/addon-context-linux/releases/download/v6.2.0/one-context-6.2.0_1.txz"
-
-if zpool list -Ho name $ZPOOL 2>/dev/null; then
-	echo "The pool $ZPOOL is already imported." >&2
-	exit 1
-fi
-
-cleanup() {
-	sync || true
-	umount /mnt/dev || true
-	zpool export $ZPOOL || true
-	mdconfig -du md0 || true
-}
-trap cleanup EXIT
-
-if [ "$(whoami)" != 'root' ]; then
-	echo "This script must be run as root." >&2
-	exit 1
-fi
-
-env ASSUME_ALWAYS_YES=YES pkg install -y qemu-tools
-
-# Allocate and partition/format disk image.
-# We use "legacy boot", aka BIOS boot
-# Preferably, we'd use EFI boot here, check the FreeBSD wiki link in the header
-# to see how to make that change, but make the EFI partition larger
-disk=$(mktemp)
-truncate -s 6G $disk
-mdconfig -a -t vnode -f $disk -u md0
-gpart create -s gpt /dev/md0
-gpart add -t freebsd-boot -l bootfs -b 40 -s 512K md0
-gpart bootcode -b /boot/pmbr -p /boot/gptzfsboot -i 1 md0
-gpart add -t freebsd-zfs -l zfs0 -b 1M -s 5G md0
-zpool create -O compression=on -o ashift=12 -o altroot=/mnt -m none $ZPOOL md0p2
-
-zfs create -o mountpoint=none                                  $ZPOOL/ROOT
-# We set zstd-19 so our image will become smaller, at the cost of a longer build time
-# At the end, we remove zstd-19 again, but all files already written will remain zstd-19 compressed
-zfs create -o mountpoint=/ -o canmount=noauto -o compression=zstd-19 $ZPOOL/ROOT/default
-mount -t zfs $ZPOOL/ROOT/default /mnt
-zpool set bootfs=$ZPOOL/ROOT/default $ZPOOL
-
-zfs create -o mountpoint=/tmp  -o exec=on      -o setuid=off   $ZPOOL/tmp
-zfs create -o canmount=off -o mountpoint=/usr                  $ZPOOL/usr
-zfs create                                                     $ZPOOL/usr/home
-zfs create                     -o exec=off     -o setuid=off   $ZPOOL/usr/src
-zfs create -o mountpoint=/usr/ports            -o setuid=off   $ZPOOL/usr/ports
-zfs create -o canmount=off -o mountpoint=/var                  $ZPOOL/var
-zfs create                     -o exec=off     -o setuid=off   $ZPOOL/var/audit
-zfs create                     -o exec=off     -o setuid=off   $ZPOOL/var/crash
-zfs create                     -o exec=off     -o setuid=off   $ZPOOL/var/log
-zfs create -o atime=on         -o exec=off     -o setuid=off   $ZPOOL/var/mail
-zfs create                     -o exec=on      -o setuid=off   $ZPOOL/var/tmp
-
-ln -s /usr/home /mnt/home
-chmod 1777 /mnt/var/tmp
-chmod 1777 /mnt/tmp
-
-# Mount allocated image.
-mkdir -p /mnt/dev
-mount -t devfs devfs /mnt/dev
-
-# Download and extract base system.
-dist_files="kernel.txz base.txz"
-dist_dir="/usr/freebsd-dist/$ARCH/$RELEASE"
-
-mkdir -p "$dist_dir"
-for f in $dist_files
-do
-	fetch -m -o "$dist_dir/$f" "$DIST_BASE/$f"
-	tar -C /mnt -xJf "$dist_dir/$f"
-done
-
-# Configure new system.
-printf '# Device\tMountpoint\tFStype\tOptions\tDump\tPass#\n' >/mnt/etc/fstab
-touch /mnt/firstboot
-sysrc -f /mnt/boot/loader.conf zfs_load=YES autoboot_delay=-1
-
-sysrc -f /mnt/etc/rc.conf ntpd_enable=YES sshd_enable=YES growfs_enable=YES hostname=freebsd
-
-cp /etc/resolv.conf /mnt/etc/resolv.conf
-tzsetup -s -C /mnt UTC
-
-cat >>/mnt/etc/ssh/sshd_config <<EOF
-PermitRootLogin yes
-PasswordAuthentication no
-PermitEmptyPasswords no
-EOF
-
-# It doesn't appear to be necessary to use "latest", "quarterly" is new enough
-#mkdir -p /mnt/usr/local/etc/pkg/repos/
-#sed -es@quarterly@latest@ </mnt/etc/pkg/FreeBSD.conf >/mnt/usr/local/etc/pkg/repos/FreeBSD.conf
-
-# freebsd-update is only supported for RELEASE
-if [ "${release%-RELEASE}" != "$RELEASE" ]
-then
-	env PAGER=true /usr/sbin/freebsd-update \
-		-b /mnt \
-		--currently-running "$RELEASE" \
-		--not-running-from-cron -F \
-		fetch install
-	rm -rf /mnt/var/db/freebsd-update/*
-fi
-
-env ASSUME_ALWAYS_YES=YES pkg -c /mnt bootstrap -f
-
-fetch -m -o /mnt/one-context.txz "$ONE_CONTEXT_PKG_URL"
-# OpenNebula has dependencies, but these are not included in the package for some reason
-# https://github.com/OpenNebula/addon-context-linux/blob/40efc929487b2955e6f32643853a5cdc93c548da/targets.sh#L25
-# It would be useful to see if there is an alternative to OpenNebula without so many dependencies,
-# so we can run on FreeBSD base, and avoid breaking OpenNebula when the admin removes a dependency.
-env ASSUME_ALWAYS_YES=YES pkg -c /mnt install sudo bash curl base64 ruby open-vm-tools-nox11 gawk virt-what one-context.txz
-env ASSUME_ALWAYS_YES=YES pkg -c /mnt clean --all
-rm /mnt/one-context.txz
-
-# Remove zstd-19 again, as it would be too slow for daily use.
-# But all files that were already writtne will remain zstd-19 compressed.
-# zstd-19 is slow to compress but fast to read.
-zfs inherit compression $ZPOOL/ROOT/default
-
-trap : EXIT
-cleanup
-
-mkdir -p "$ARCH"
-qemu-img convert -f raw -O qcow2 "$disk" "$IMAGE_PATH"
-rm "$disk"
-
-# Filesystem will be enlarged by growfs(7) on next startup
-qemu-img resize "$IMAGE_PATH" "$IMAGE_SIZE"