diff --git a/system_setup/install.sh b/system_setup/install.sh
index e289bd2..df3b9a8 100755
--- a/system_setup/install.sh
+++ b/system_setup/install.sh
@@ -79,6 +79,13 @@ PT_MNT=()   # /home | -
 PT_FREE=()  # free MiB (integer)
 PT_OK=()    # 1 = shrinkable
 
+# Parallel arrays for unpartitioned free space regions, indexed 0..FS_IDX-1
+FS_IDX=0
+FS_DISK=()   # /dev/sda
+FS_START=()  # region start, MiB
+FS_END=()    # region end, MiB
+FS_SIZE=()   # region size, MiB
+
 collect_partitions() {
     local NAME SIZE FSTYPE LABEL UUID MOUNTPOINT TYPE PKNAME
 
@@ -124,6 +131,34 @@ collect_partitions() {
     done < <(lsblk -o NAME,SIZE,FSTYPE,LABEL,UUID,MOUNTPOINT,TYPE,PKNAME -p -P -n 2>/dev/null)
 }
 
+collect_free_space() {
+    local disk
+    while IFS= read -r disk; do
+        [[ -b "$disk" ]] || continue
+        while read -r s e sz; do
+            FS_DISK[$FS_IDX]="$disk"
+            FS_START[$FS_IDX]="$s"
+            FS_END[$FS_IDX]="$e"
+            FS_SIZE[$FS_IDX]="$sz"
+            (( FS_IDX++ )) || true
+        done < <(
+            parted -s "$disk" -m unit MiB print free 2>/dev/null \
+            | awk -F'[;:]' -v min="$SHRINK_MIB" '
+                $1+0 > 0 {
+                    for (i = 1; i <= NF; i++) {
+                        if ($i == "free") {
+                            start=$2; end=$3; size=$4;
+                            gsub(/MiB/,"",start); gsub(/MiB/,"",end); gsub(/MiB/,"",size);
+                            s=int(start+0); e=int(end+0); sz=int(size+0);
+                            if (sz >= min) print s " " e " " sz;
+                            break
+                        }
+                    }
+                }'
+        )
+    done < <(lsblk -d -p -n -o NAME 2>/dev/null)
+}
+
 # ── Table display ─────────────────────────────────────────────────────────────
 
 show_table() {
@@ -160,6 +195,25 @@ show_table() {
     echo
 }
 
+show_free_table() {
+    [[ $FS_IDX -gt 0 ]] || return
+    echo
+    echo "Unpartitioned free space regions (>= ${SHRINK_MIB} MiB):"
+    hr
+    printf "  %-4s  %-14s  %-12s  %-12s  %s\n" "#" "Disk" "Start (MiB)" "End (MiB)" "Size (MiB)"
+    hr
+    for (( i=0; i<FS_IDX; i++ )); do
+        printf "  %-4s  %-14s  %-12s  %-12s  %s\n" \
+            "$((i+1))" \
+            "${FS_DISK[$i]}" \
+            "${FS_START[$i]}" \
+            "${FS_END[$i]}" \
+            "${FS_SIZE[$i]}"
+    done
+    hr
+    echo
+}
+
 # ── Partition geometry via parted -m ─────────────────────────────────────────
 
 part_end_mib() {
@@ -187,116 +241,154 @@ new_part_device() {
 require_root
 check_tools
 
-info "Scanning partitions for shrinkable ext4 / btrfs volumes..."
+info "Scanning for shrinkable partitions and unpartitioned free space..."
 collect_partitions
+collect_free_space
 
-[[ $PT_IDX -gt 0 ]] || die "No ext4 or btrfs partitions found on this system."
+[[ $PT_IDX -gt 0 || $FS_IDX -gt 0 ]] \
+    || die "No ext4 or btrfs partitions and no free disk space found on this system."
 
-show_table
-
-# Count shrinkable
+# Count shrinkable partitions
 shrink_count=0
 for (( i=0; i<PT_IDX; i++ )); do [[ "${PT_OK[$i]}" == "1" ]] && (( shrink_count++ )) || true; done
-[[ $shrink_count -gt 0 ]] || die "No shrinkable partitions found. A non-root ext4 or btrfs partition needs at least ${MIN_FREE_MIB} MiB free."
+
+[[ $PT_IDX -gt 0 ]] && show_table
+show_free_table
+
+[[ $shrink_count -gt 0 || $FS_IDX -gt 0 ]] \
+    || die "No shrinkable partitions and no free space found. A non-root ext4 or btrfs partition needs at least ${MIN_FREE_MIB} MiB free."
 
 # ── Selection ─────────────────────────────────────────────────────────────────
 
+MODE=""   # "freespace" | "shrink"
 SEL=-1
+
 while true; do
-    read -r -p "Enter number of partition to shrink, or q to quit: " INPUT
+    echo
+    if [[ $FS_IDX -gt 0 && $shrink_count -gt 0 ]]; then
+        read -r -p "Enter  f<n>  to use free space,  s<n>  to shrink a partition, or  q  to quit: " INPUT
+    elif [[ $FS_IDX -gt 0 ]]; then
+        read -r -p "Enter number of free space region to use, or  q  to quit: " INPUT
+        [[ "$INPUT" =~ ^[0-9]+$ ]] && INPUT="f${INPUT}"
+    else
+        read -r -p "Enter number of partition to shrink, or  q  to quit: " INPUT
+        [[ "$INPUT" =~ ^[0-9]+$ ]] && INPUT="s${INPUT}"
+    fi
+
     [[ "$INPUT" =~ ^[qQ]$ ]] && { echo "Aborted."; exit 0; }
-    [[ "$INPUT" =~ ^[0-9]+$ ]] || { echo "  Please enter a number."; continue; }
-    local_i=$(( INPUT - 1 ))
-    (( local_i >= 0 && local_i < PT_IDX )) || { echo "  Number out of range."; continue; }
-    [[ "${PT_OK[$local_i]}" == "1" ]] || { echo "  That partition cannot be shrunk (see marks above)."; continue; }
-    SEL=$local_i
-    break
+
+    if [[ "$INPUT" =~ ^[fF]([0-9]+)$ ]]; then
+        local_i=$(( ${BASH_REMATCH[1]} - 1 ))
+        (( local_i >= 0 && local_i < FS_IDX )) || { echo "  Number out of range."; continue; }
+        MODE="freespace"; SEL=$local_i; break
+
+    elif [[ "$INPUT" =~ ^[sS]([0-9]+)$ ]]; then
+        local_i=$(( ${BASH_REMATCH[1]} - 1 ))
+        (( local_i >= 0 && local_i < PT_IDX )) || { echo "  Number out of range."; continue; }
+        [[ "${PT_OK[$local_i]}" == "1" ]] || { echo "  That partition cannot be shrunk (see marks above)."; continue; }
+        MODE="shrink"; SEL=$local_i; break
+
+    else
+        echo "  Invalid input."
+    fi
 done
 
-S_DEV="${PT_DEV[$SEL]}"
-S_DISK="${PT_DISK[$SEL]}"
-S_PNUM="${PT_PNUM[$SEL]}"
-S_FS="${PT_FS[$SEL]}"
-S_MNT="${PT_MNT[$SEL]}"
+# ── Confirm ───────────────────────────────────────────────────────────────────
 
 echo
-echo "  Partition : $S_DEV  (${PT_FS[$SEL]}, ${PT_SIZE[$SEL]}, ${PT_FREE[$SEL]} MiB free)"
-echo "  Disk      : $S_DISK   Partition number: $S_PNUM"
-echo "  Mountpoint: $S_MNT"
-echo
-echo "  $S_DEV will be shrunk by ${SHRINK_MIB} MiB."
-echo "  A new ${SHRINK_MIB} MiB BTRFS partition labeled OEMDRV will be created."
-echo "  It will be mounted at $MOUNT_POINT and the repository cloned into it."
+if [[ "$MODE" == "freespace" ]]; then
+    WORK_DISK="${FS_DISK[$SEL]}"
+    OEMDRV_START="${FS_START[$SEL]}"
+    OEMDRV_END=$(( FS_START[$SEL] + SHRINK_MIB ))
+    echo "  Disk        : $WORK_DISK"
+    echo "  Free region : ${FS_START[$SEL]} MiB – ${FS_END[$SEL]} MiB  (${FS_SIZE[$SEL]} MiB available)"
+    echo "  New OEMDRV  : ${OEMDRV_START} MiB – ${OEMDRV_END} MiB  (${SHRINK_MIB} MiB)"
+    echo "  It will be mounted at $MOUNT_POINT and the repository cloned into it."
+else
+    S_DEV="${PT_DEV[$SEL]}"
+    S_DISK="${PT_DISK[$SEL]}"
+    S_PNUM="${PT_PNUM[$SEL]}"
+    S_FS="${PT_FS[$SEL]}"
+    S_MNT="${PT_MNT[$SEL]}"
+    WORK_DISK="$S_DISK"
+    echo "  Partition : $S_DEV  (${PT_FS[$SEL]}, ${PT_SIZE[$SEL]}, ${PT_FREE[$SEL]} MiB free)"
+    echo "  Disk      : $S_DISK   Partition number: $S_PNUM"
+    echo "  Mountpoint: $S_MNT"
+    echo
+    echo "  $S_DEV will be shrunk by ${SHRINK_MIB} MiB."
+    echo "  A new ${SHRINK_MIB} MiB BTRFS partition labeled OEMDRV will be created."
+    echo "  It will be mounted at $MOUNT_POINT and the repository cloned into it."
+fi
 echo
 read -r -p "  Type YES (uppercase) to confirm, anything else to abort: " CONFIRM
 [[ "$CONFIRM" == "YES" ]] || { echo "Aborted."; exit 0; }
 
-# ── Geometry ──────────────────────────────────────────────────────────────────
-
-info "Reading partition geometry on $S_DISK..."
-
-CURR_END=$(part_end_mib "$S_DISK" "$S_PNUM")
-CURR_START=$(part_start_mib "$S_DISK" "$S_PNUM")
-[[ -n "$CURR_END" && -n "$CURR_START" ]] || die "Could not read geometry for partition $S_PNUM on $S_DISK."
-
-NEW_END=$(( CURR_END - SHRINK_MIB ))
-NEW_FS_MIB=$(( NEW_END - CURR_START ))
-OEMDRV_START=$NEW_END
-OEMDRV_END=$CURR_END
-
-echo "  Current partition : ${CURR_START} MiB – ${CURR_END} MiB"
-echo "  After shrink      : ${CURR_START} MiB – ${NEW_END} MiB  (filesystem: ${NEW_FS_MIB} MiB)"
-echo "  New OEMDRV        : ${OEMDRV_START} MiB – ${OEMDRV_END} MiB  (${SHRINK_MIB} MiB)"
-
-# ── Unmount ───────────────────────────────────────────────────────────────────
+# ── Shrink path: geometry + filesystem resize + partition table update ─────────
 
 WAS_MOUNTED=0
 ORIG_MNT=""
-if [[ "$S_MNT" != "-" && -n "$S_MNT" ]]; then
-    info "Unmounting $S_DEV from $S_MNT..."
-    ORIG_MNT="$S_MNT"
-    umount "$S_DEV" || die "Cannot unmount $S_DEV. Close all open files and try again."
-    WAS_MOUNTED=1
+
+if [[ "$MODE" == "shrink" ]]; then
+    info "Reading partition geometry on $S_DISK..."
+
+    CURR_END=$(part_end_mib "$S_DISK" "$S_PNUM")
+    CURR_START=$(part_start_mib "$S_DISK" "$S_PNUM")
+    [[ -n "$CURR_END" && -n "$CURR_START" ]] \
+        || die "Could not read geometry for partition $S_PNUM on $S_DISK."
+
+    NEW_END=$(( CURR_END - SHRINK_MIB ))
+    NEW_FS_MIB=$(( NEW_END - CURR_START ))
+    OEMDRV_START=$NEW_END
+    OEMDRV_END=$CURR_END
+
+    echo "  Current partition : ${CURR_START} MiB – ${CURR_END} MiB"
+    echo "  After shrink      : ${CURR_START} MiB – ${NEW_END} MiB  (filesystem: ${NEW_FS_MIB} MiB)"
+    echo "  New OEMDRV        : ${OEMDRV_START} MiB – ${OEMDRV_END} MiB  (${SHRINK_MIB} MiB)"
+
+    if [[ "$S_MNT" != "-" && -n "$S_MNT" ]]; then
+        info "Unmounting $S_DEV from $S_MNT..."
+        ORIG_MNT="$S_MNT"
+        umount "$S_DEV" || die "Cannot unmount $S_DEV. Close all open files and try again."
+        WAS_MOUNTED=1
+    fi
+
+    if [[ "$S_FS" == "ext4" ]]; then
+        info "Running e2fsck on $S_DEV..."
+        e2fsck -f "$S_DEV" || die "e2fsck found errors on $S_DEV. Fix them before retrying."
+
+        info "Shrinking ext4 filesystem to ${NEW_FS_MIB} MiB..."
+        resize2fs "$S_DEV" "${NEW_FS_MIB}M" || die "resize2fs failed."
+
+    elif [[ "$S_FS" == "btrfs" ]]; then
+        info "Shrinking btrfs filesystem on $S_DEV to ${NEW_FS_MIB} MiB..."
+        TMP_MNT=$(mktemp -d /tmp/oemdrv_btrfs.XXXXXX)
+        mount "$S_DEV" "$TMP_MNT" || { rmdir "$TMP_MNT"; die "Cannot mount $S_DEV for btrfs resize."; }
+        btrfs filesystem resize "${NEW_FS_MIB}m" "$TMP_MNT" \
+            || { umount "$TMP_MNT"; rmdir "$TMP_MNT"; die "btrfs filesystem resize failed."; }
+        sync
+        umount "$TMP_MNT" && rmdir "$TMP_MNT"
+    fi
+
+    info "Shrinking partition $S_PNUM to ${NEW_END} MiB in partition table..."
+    parted -s "$S_DISK" resizepart "$S_PNUM" "${NEW_END}MiB" \
+        || die "parted resizepart failed."
 fi
 
-# ── Filesystem resize ─────────────────────────────────────────────────────────
+# ── Create OEMDRV partition ───────────────────────────────────────────────────
 
-if [[ "$S_FS" == "ext4" ]]; then
-    info "Running e2fsck on $S_DEV..."
-    e2fsck -f "$S_DEV" || die "e2fsck found errors on $S_DEV. Fix them before retrying."
+info "Creating new OEMDRV partition (${OEMDRV_START}–${OEMDRV_END} MiB) on $WORK_DISK..."
+parted -s "$WORK_DISK" mkpart primary btrfs "${OEMDRV_START}MiB" "${OEMDRV_END}MiB" \
+    || die "parted mkpart failed. Check that the target area is free space on $WORK_DISK."
 
-    info "Shrinking ext4 filesystem to ${NEW_FS_MIB} MiB..."
-    resize2fs "$S_DEV" "${NEW_FS_MIB}M" || die "resize2fs failed."
-
-elif [[ "$S_FS" == "btrfs" ]]; then
-    info "Shrinking btrfs filesystem on $S_DEV to ${NEW_FS_MIB} MiB..."
-    TMP_MNT=$(mktemp -d /tmp/oemdrv_btrfs.XXXXXX)
-    mount "$S_DEV" "$TMP_MNT" || { rmdir "$TMP_MNT"; die "Cannot mount $S_DEV for btrfs resize."; }
-    btrfs filesystem resize "${NEW_FS_MIB}m" "$TMP_MNT" \
-        || { umount "$TMP_MNT"; rmdir "$TMP_MNT"; die "btrfs filesystem resize failed."; }
-    sync
-    umount "$TMP_MNT" && rmdir "$TMP_MNT"
-fi
-
-# ── Partition table update ────────────────────────────────────────────────────
-
-info "Shrinking partition $S_PNUM to ${NEW_END} MiB in partition table..."
-parted -s "$S_DISK" resizepart "$S_PNUM" "${NEW_END}MiB" \
-    || die "parted resizepart failed."
-
-info "Creating new OEMDRV partition (${OEMDRV_START}–${OEMDRV_END} MiB)..."
-parted -s "$S_DISK" mkpart primary btrfs "${OEMDRV_START}MiB" "${OEMDRV_END}MiB" \
-    || die "parted mkpart failed. Check that the target area is free space on $S_DISK."
-
-partprobe "$S_DISK"
+partprobe "$WORK_DISK"
 sleep 1
 
 # Determine new partition number (highest on the disk after partprobe)
-NEW_PNUM=$(parted -s "$S_DISK" -m unit MiB print 2>/dev/null \
+NEW_PNUM=$(parted -s "$WORK_DISK" -m unit MiB print 2>/dev/null \
     | awk -F: '/^[0-9]/{n=$1} END{print n}')
-[[ -n "$NEW_PNUM" ]] || die "Could not determine new partition number on $S_DISK."
+[[ -n "$NEW_PNUM" ]] || die "Could not determine new partition number on $WORK_DISK."
 
-OEMDRV_DEV=$(new_part_device "$S_DISK" "$NEW_PNUM")
+OEMDRV_DEV=$(new_part_device "$WORK_DISK" "$NEW_PNUM")
 [[ -b "$OEMDRV_DEV" ]] || die "New partition device $OEMDRV_DEV not found after partprobe."
 
 info "New partition device: $OEMDRV_DEV"
@@ -306,7 +398,7 @@ info "New partition device: $OEMDRV_DEV"
 info "Formatting $OEMDRV_DEV as BTRFS (label: $OEMDRV_LABEL)..."
 mkfs.btrfs -f -L "$OEMDRV_LABEL" "$OEMDRV_DEV" || die "mkfs.btrfs failed."
 
-# ── Remount original partition ────────────────────────────────────────────────
+# ── Remount original partition (shrink path only) ─────────────────────────────
 
 if [[ $WAS_MOUNTED -eq 1 && -n "$ORIG_MNT" ]]; then
     info "Remounting $S_DEV to $ORIG_MNT..."