Add attach-drives.sh: auto-generate qm set commands for data drives

Scans /dev/sd?, skips OS drive (sda) and USB sticks (<100 GiB), checks
which drives are already attached to any VM, then prints (or applies with
--apply) the qm set commands for the next free scsi slot on the target VM.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01CTRZQmUSrYXFC6WkcypYPv

scripts/attach-drives.sh

@@ -0,0 +1,143 @@
+#!/usr/bin/env bash
+# Generate qm set commands to attach data drives to a Proxmox VM.
+# Run on the Proxmox host. Skips the OS drive (sda) and any drives
+# already attached to any VM.
+#
+# Usage:
+#   ./attach-drives.sh              # preview commands (dry run)
+#   ./attach-drives.sh --apply      # actually run the commands
+#   ./attach-drives.sh --vm 100     # target a specific VM (default: 100)
+#
+# Example:
+#   ./attach-drives.sh --vm 100 --apply
+
+set -euo pipefail
+
+VM_ID=100
+APPLY=false
+
+while [[ $# -gt 0 ]]; do
+  case "$1" in
+    --vm)    VM_ID="$2"; shift 2 ;;
+    --apply) APPLY=true; shift ;;
+    *)       echo "Usage: $0 [--vm <id>] [--apply]"; exit 1 ;;
+  esac
+done
+
+# ── Find drives already attached to any VM ────────────────────────────────────
+
+attached_ids=()
+for conf in /etc/pve/qemu-server/*.conf; do
+  while IFS= read -r line; do
+    if [[ "$line" =~ /dev/disk/by-id/([^,]+) ]]; then
+      attached_ids+=("${BASH_REMATCH[1]}")
+    fi
+  done < "$conf"
+done
+
+is_attached() {
+  local id="$1"
+  for a in "${attached_ids[@]:-}"; do
+    [[ "$a" == "$id" ]] && return 0
+  done
+  return 1
+}
+
+# ── Find next free scsi slot for the target VM ────────────────────────────────
+
+next_slot() {
+  local conf="/etc/pve/qemu-server/${VM_ID}.conf"
+  local slot=1
+  while grep -q "^scsi${slot}:" "$conf" 2>/dev/null; do
+    (( slot++ ))
+  done
+  echo "$slot"
+}
+
+# ── Inventory all block devices ───────────────────────────────────────────────
+
+echo "=== Available data drives (not yet attached to any VM) ==="
+echo ""
+printf "%-12s %-10s %-35s %s\n" "DEVICE" "SIZE" "BY-ID PATH" "MODEL"
+printf "%-12s %-10s %-35s %s\n" "------" "----" "----------" "-----"
+
+candidates=()
+
+for dev in /dev/sd?; do
+  [[ -b "$dev" ]] || continue
+  name=$(basename "$dev")
+
+  # Skip OS drive (sda — the PERC RAID array Proxmox is installed on)
+  [[ "$name" == "sda" ]] && continue
+
+  # Skip USB devices (small drives < 100G are likely USB sticks)
+  size_bytes=$(lsblk -dn -o SIZE -b "$dev" 2>/dev/null || echo 0)
+  size_human=$(lsblk -dn -o SIZE "$dev" 2>/dev/null || echo "?")
+  if [[ "$size_bytes" -lt 107374182400 ]]; then   # < 100 GiB
+    printf "%-12s %-10s %-35s %s\n" "$name" "$size_human" "(skipped — looks like USB stick)" ""
+    continue
+  fi
+
+  model=$(cat "/sys/block/${name}/device/model" 2>/dev/null | xargs || echo "?")
+
+  # Find best by-id (prefer ata- over scsi-)
+  byid=""
+  for link in /dev/disk/by-id/ata-* /dev/disk/by-id/scsi-3*; do
+    [[ -L "$link" ]] || continue
+    [[ "$(readlink -f "$link")" == "$dev" ]] || continue
+    [[ "$link" =~ -part ]] && continue
+    byid=$(basename "$link")
+    [[ "$byid" == ata-* ]] && break   # prefer ata- if found
+  done
+
+  if [[ -z "$byid" ]]; then
+    printf "%-12s %-10s %-35s %s\n" "$name" "$size_human" "(no by-id found — skip)" "$model"
+    continue
+  fi
+
+  if is_attached "$byid"; then
+    printf "%-12s %-10s %-35s %s\n" "$name" "$size_human" "${byid} [already attached]" "$model"
+    continue
+  fi
+
+  printf "%-12s %-10s %-35s %s\n" "$name" "$size_human" "$byid" "$model"
+  candidates+=("$byid")
+done
+
+echo ""
+
+if [[ ${#candidates[@]} -eq 0 ]]; then
+  echo "No unattached data drives found."
+  exit 0
+fi
+
+# ── Generate qm set commands ──────────────────────────────────────────────────
+
+echo "=== Commands to attach to VM ${VM_ID} ==="
+echo ""
+
+slot=$(next_slot)
+cmds=()
+for byid in "${candidates[@]}"; do
+  cmd="qm set ${VM_ID} --scsi${slot} /dev/disk/by-id/${byid}"
+  cmds+=("$cmd")
+  echo "  $cmd"
+  (( slot++ ))
+done
+
+echo ""
+
+if $APPLY; then
+  echo "--- Applying ---"
+  for cmd in "${cmds[@]}"; do
+    echo "  Running: $cmd"
+    eval "$cmd"
+  done
+  echo ""
+  echo "Done. Verify with:"
+  echo "  grep scsi /etc/pve/qemu-server/${VM_ID}.conf"
+else
+  echo "Dry run — no changes made. Re-run with --apply to attach drives."
+  echo ""
+  echo "  ./attach-drives.sh --vm ${VM_ID} --apply"
+fi