diff --git a/buildroot-external/rootfs-overlay/usr/bin/datactl b/buildroot-external/rootfs-overlay/usr/bin/datactl
index 4a31fb9f5..152b942f3 100755
--- a/buildroot-external/rootfs-overlay/usr/bin/datactl
+++ b/buildroot-external/rootfs-overlay/usr/bin/datactl
@@ -36,13 +36,11 @@ if [ "${1}" = "move" ] && [ -e "${2}" ]; then
         exit 1
     fi
 
-    sgdisk --zap-all "${NEW_DEVICE_ROOT}"
-    sgdisk \
-        -n "0:0:0" \
-        -c "0:hassos-data-external" \
-        -t "0:0FC63DAF-8483-4772-8E79-3D69D8477DE4" \
-        -u "0:a52a4597-fa3a-4851-aefd-2fbe9f849079" \
-        "${NEW_DEVICE_ROOT}"
+    # Create GPT partition table with a single data partition
+    cat << EOF | sfdisk --wipe-partitions=always --wipe=always "${NEW_DEVICE_ROOT}"
+label: gpt
+uuid=a52a4597-fa3a-4851-aefd-2fbe9f849079, type=0FC63DAF-8483-4772-8E79-3D69D8477DE4, name=hassos-data-external
+EOF
 
     # Since we create a new partition table etc. we are guaranteed the target
     # partition is partition 1
@@ -51,7 +49,7 @@ if [ "${1}" = "move" ] && [ -e "${2}" ]; then
 
     if [ "${NEW_DEVICE_PART_SIZE}" -lt "${OLD_DEVICE_PART_SIZE}" ]; then
         echo "[INFO] Target device too small!"
-        sgdisk --zap-all "${NEW_DEVICE_ROOT}"
+        echo "label: gpt" | sfdisk "${NEW_DEVICE_ROOT}"
         exit 1
     fi
 
diff --git a/buildroot-external/rootfs-overlay/usr/lib/systemd/system/hassos-data.service b/buildroot-external/rootfs-overlay/usr/lib/systemd/system/hassos-data.service
index f2b4660c0..6f8b2136f 100644
--- a/buildroot-external/rootfs-overlay/usr/lib/systemd/system/hassos-data.service
+++ b/buildroot-external/rootfs-overlay/usr/lib/systemd/system/hassos-data.service
@@ -3,7 +3,7 @@ Description=Home Assistant OS data partition migration
 DefaultDependencies=no
 RefuseManualStart=true
 RefuseManualStop=true
-Requires=mnt-overlay.mount dev-disk-by\x2dlabel-hassos\x2ddata.device dev-disk-by\x2dpartlabel-hassos\x2ddata\x2dexternal.device
+Requires=mnt-overlay.mount dev-disk-by\x2dlabel-hassos\x2ddata.device
 Wants=hassos-expand.service
 After=mnt-overlay.mount dev-disk-by\x2dlabel-hassos\x2ddata.device systemd-fsck@dev-disk-by\x2dlabel-hassos\x2ddata.service dev-disk-by\x2dpartlabel-hassos\x2ddata\x2dexternal.device
 Before=hassos-expand.service
diff --git a/buildroot-external/rootfs-overlay/usr/libexec/hassos-data b/buildroot-external/rootfs-overlay/usr/libexec/hassos-data
index 83a38c556..671f779b5 100755
--- a/buildroot-external/rootfs-overlay/usr/libexec/hassos-data
+++ b/buildroot-external/rootfs-overlay/usr/libexec/hassos-data
@@ -7,6 +7,16 @@ set -e
 # Rely on systemd-udev symlinks to find current data partition by fs label
 OLD_DEVICE_CHILD="$(readlink -f "/dev/disk/by-label/hassos-data")"
 
+# We cannot rely on systemd Wants/Requires since this is evaluated before
+# ConditionPathExists, and would make us wait for an external device on
+# every boot.
+# Instead, just start the unit here, which makes sure a device with the
+# partlabel "hassos-data-external" is present.
+if ! systemctl start "dev-disk-by\\x2dpartlabel-hassos\\x2ddata\\x2dexternal.device"; then
+    echo "[ERROR] External data device ${NEW_DEVICE} not found!"
+    exit 1
+fi
+
 # Rely on systemd-udev symlinks to find external data partition by partlabel
 NEW_DEVICE_CHILD="$(readlink -f "/dev/disk/by-partlabel/hassos-data-external")"