Fix PXE netboot installer hanging at boot (ISO/netboot module conflict)

The netboot build composed ./modules/installer/iso.nix (which pulls in
nixpkgs' installation-cd-minimal.nix) together with nixpkgs'
netboot-minimal.nix. Both installation-cd-base.nix and netboot.nix set
fileSystems."/" via the identical lib.mkImageMediaOverride (mkOverride
60) priority - genuinely conflicting root-filesystem strategies
(ISO-by-label vs. netboot-tmpfs) at the same priority, and the ISO one
was winning. Every netboot boot hung waiting for a device that can
never exist outside a real CD/USB:

  A start job is running for /dev/disk/by-label/nixos-minimal-...

Reproduced live: deployed a scratch lxc-pxe-boot on pve-test, pulled its
built kernel/initrd, and booted them directly with QEMU to confirm the
hang and capture full console output. netboot-minimal.nix's own chain
(netboot-base.nix) already imports profiles/installation-device.nix
independently, so common.nix's initialHashedPassword override still
applies correctly with iso.nix removed from this composition. Rebuilt
and re-booted the same way after the fix - full boot to a working shell
with SSH up, no hang.

flake.nix

@@ -119,10 +119,24 @@
 
       # Same installer environment, built as netboot (kernel + initrd +
       # iPXE script) instead of an ISO — this is what packages.pxe bundles.
+      #
+      # Deliberately imports common.nix directly, NOT ./modules/installer/iso.nix
+      # (which pulls in nixpkgs' installation-cd-minimal.nix) -- confirmed live
+      # that composing the ISO module together with netboot-minimal.nix hangs
+      # every boot waiting for a device that can never exist on a netboot
+      # client ("A start job is running for /dev/disk/by-label/nixos-minimal-...").
+      # Both installation-cd-base.nix and netboot.nix set fileSystems."/" via
+      # the identical lib.mkImageMediaOverride (mkOverride 60) priority --
+      # genuinely conflicting root-filesystem strategies (ISO-by-label vs.
+      # netboot-tmpfs) at the same priority, and the ISO one was winning.
+      # netboot-minimal.nix's own chain (netboot-base.nix) already imports
+      # profiles/installation-device.nix independently, so common.nix's
+      # initialHashedPassword override (which assumes that profile is
+      # present) still applies correctly without iso.nix in the mix.
       netbootSystem = nixpkgs.lib.nixosSystem {
         inherit system;
         modules = [
-          ./modules/installer/iso.nix
+          ./modules/installer/common.nix
           ({ modulesPath, ... }: {
             imports = [
               (modulesPath + "/installer/netboot/netboot-minimal.nix")

scripts/proxmox/clone-pve1-to-pve-test.sh

@@ -0,0 +1,221 @@
+#!/usr/bin/env bash
+# Ad hoc clone of a single VM/CT from pve1 (production) to pve-test
+# (sandbox), via vzdump + qmrestore/pct restore -- not a general-purpose
+# backup tool, just a quick "give me a disposable copy of this thing on
+# pve-test" for testing against real-ish data without touching prod.
+#
+# Flow:
+#   1. vzdump the resource on pve1 into its "local" storage (--mode
+#      snapshot by default, so the source keeps running throughout --
+#      see --mode below for when that's not possible).
+#   2. Stream the resulting archive straight from pve1 to pve-test
+#      (ssh pve1 cat ... | ssh pve-test cat > ...) -- this machine is
+#      just the relay, no separate on-disk staging copy here.
+#   3. qmrestore / pct restore it on pve-test under --new-vmid (default:
+#      same VMID as the source -- pve-test is a separate node/cluster, so
+#      no collision unless that VMID is already in use there too).
+#      Always restored with --unique 1 (fresh MAC addresses) since the
+#      source is typically still running on the same LAN -- restoring
+#      with the *same* MAC would put two live guests on the wire with
+#      identical hardware addresses.
+#   4. Delete the vzdump archive from pve1's local storage and the
+#      relayed copy on pve-test, so neither node accumulates ad hoc
+#      backup files from this script. Only the pve1 original is
+#      preserved on any failure after step 1, so a failed
+#      transfer/restore can be retried without re-running the backup.
+#
+# This script's own defaults are pve1 -> pve-test, unlike
+# create-proxmox-resource.sh's --node (which defaults to production) --
+# see CLAUDE.md's "Two Proxmox nodes" section. pve1 is only ever touched
+# here after typing the source VMID back to confirm; pve-test is treated
+# as disposable, matching this repo's usual policy for that node.
+#
+# See --help for the full option list.
+set -euo pipefail
+
+repo_root="$(cd "$(dirname "$0")/../.." && pwd)"
+# shellcheck source=../env.sh
+source "${repo_root}/scripts/env.sh"
+# shellcheck source=../lib/confirm.sh
+source "${repo_root}/scripts/lib/confirm.sh"
+
+usage() {
+  cat <<EOF
+Usage: $0 --vmid <n> [options]
+
+  --vmid <n>              Required: VMID on the source node to clone.
+                           Kind (qemu VM vs LXC CT) is auto-detected.
+  --new-vmid <n>           VMID to restore as on the target node
+                           (default: same as --vmid).
+  --mode snapshot|suspend|stop
+                           vzdump backup mode (default: snapshot -- the
+                           source resource keeps running throughout;
+                           requires snapshot-capable storage, e.g.
+                           ZFS/LVM-thin/Ceph/qcow2). Fall back to
+                           "suspend" (brief pause) or "stop" (source
+                           goes down for the duration) if the source's
+                           storage doesn't support live snapshots --
+                           vzdump's own error will say so.
+  --source-node <host>      (default: \$PVE1_HOST, ${PVE1_HOST})
+  --target-node <host>       (default: \$PVE_TEST_HOST, ${PVE_TEST_HOST})
+  --source-storage <pool>      Where vzdump writes the backup on the
+                               source node (default: local).
+  --target-storage <pool>       Where the restored disk/rootfs lands on
+                               the target node (default: \$PROXMOX_STORAGE, ${PROXMOX_STORAGE}).
+  --keep-backup                  Don't delete the vzdump archive from
+                                 either node afterward (debugging aid).
+  --yes                            Skip the typed VMID confirmation
+                                   before touching the source node.
+  --dry-run                          Print the full plan and skip every
+                                     mutating step (vzdump, transfer,
+                                     restore, delete) and the confirm
+                                     prompt. Still makes read-only SSH
+                                     calls to look up the source kind
+                                     and check the target VMID is free
+                                     -- harmless on either node.
+  -h, --help
+EOF
+}
+
+vmid=""
+new_vmid=""
+mode="snapshot"
+source_node="$PVE1_HOST"
+target_node="$PVE_TEST_HOST"
+source_storage="local"
+target_storage="$PROXMOX_STORAGE"
+keep_backup=0
+skip_confirm=0
+dry_run=0
+
+while [[ $# -gt 0 ]]; do
+  case "$1" in
+  --vmid) vmid="$2"; shift 2 ;;
+  --new-vmid) new_vmid="$2"; shift 2 ;;
+  --mode) mode="$2"; shift 2 ;;
+  --source-node) source_node="$2"; shift 2 ;;
+  --target-node) target_node="$2"; shift 2 ;;
+  --source-storage) source_storage="$2"; shift 2 ;;
+  --target-storage) target_storage="$2"; shift 2 ;;
+  --keep-backup) keep_backup=1; shift ;;
+  --yes) skip_confirm=1; shift ;;
+  --dry-run) dry_run=1; shift ;;
+  -h | --help) usage; exit 0 ;;
+  *) echo "Unknown option: $1" >&2; usage >&2; exit 1 ;;
+  esac
+done
+
+if [[ -z "$vmid" ]]; then
+  echo "ERROR: --vmid is required." >&2
+  usage >&2
+  exit 1
+fi
+if [[ "$mode" != "snapshot" && "$mode" != "suspend" && "$mode" != "stop" ]]; then
+  echo "ERROR: --mode must be snapshot, suspend, or stop." >&2
+  exit 1
+fi
+[[ -z "$new_vmid" ]] && new_vmid="$vmid"
+
+source_target="${PROXMOX_SSH_USER}@${source_node}"
+target_target="${PROXMOX_SSH_USER}@${target_node}"
+
+# No dry-run wrapper needed for the calls below: every mutating step
+# (vzdump, transfer, restore, delete) is reached only after the --dry-run
+# early-exit further down, so a plain `ssh` call is never in the dry-run
+# path.
+
+# --- identify the resource kind on the source node -----------------------
+echo "==> Looking up VMID ${vmid} on ${source_node}..."
+kind=""
+if ssh "$source_target" "qm status ${vmid}" >/dev/null 2>&1; then
+  kind="vm"
+elif ssh "$source_target" "pct status ${vmid}" >/dev/null 2>&1; then
+  kind="lxc"
+else
+  echo "ERROR: VMID ${vmid} doesn't exist on ${source_node} as either a VM or CT." >&2
+  exit 1
+fi
+echo "VMID ${vmid} on ${source_node} is a ${kind}."
+
+# --- refuse to clobber an existing resource on the target node -----------
+if ssh "$target_target" "qm status ${new_vmid}" >/dev/null 2>&1 \
+  || ssh "$target_target" "pct status ${new_vmid}" >/dev/null 2>&1; then
+  echo "ERROR: VMID ${new_vmid} already exists on ${target_node}. Pass --new-vmid" >&2
+  echo "with a free ID, or remove the existing resource there first." >&2
+  exit 1
+fi
+
+echo
+echo "Plan:"
+echo "  source: ${kind} VMID ${vmid} on ${source_node} (storage: ${source_storage}, mode: ${mode})"
+echo "  target: VMID ${new_vmid} on ${target_node} (storage: ${target_storage}, fresh MAC via --unique)"
+[[ "$keep_backup" -eq 1 ]] && echo "  backup archives are kept on both nodes afterward (--keep-backup)"
+
+if [[ "$dry_run" -eq 1 ]]; then
+  echo
+  echo "[dry-run] No backup, transfer, restore, or delete was performed."
+  exit 0
+fi
+
+if [[ "$skip_confirm" -ne 1 ]]; then
+  echo
+  if ! confirm_typed "$vmid" "Type the source VMID (${vmid}) to confirm backing it up from ${source_node}: "; then
+    echo "Cancelled -- input didn't match ${vmid}." >&2
+    exit 1
+  fi
+fi
+
+# --- vzdump on the source node --------------------------------------------
+echo
+echo "==> Backing up VMID ${vmid} on ${source_node} (mode=${mode}, storage=${source_storage})..."
+vzdump_log="$(ssh "$source_target" \
+  "vzdump ${vmid} --mode ${mode} --storage ${source_storage} --compress zstd" 2>&1)" \
+  || {
+    echo "$vzdump_log" >&2
+    echo "ERROR: vzdump failed on ${source_node}." >&2
+    exit 1
+  }
+echo "$vzdump_log"
+
+archive="$(echo "$vzdump_log" | grep -oP "creating vzdump archive '\K[^']+" | tail -n1)"
+if [[ -z "$archive" ]]; then
+  echo "ERROR: couldn't find the archive path in vzdump's output above." >&2
+  exit 1
+fi
+archive_basename="$(basename "$archive")"
+target_tmp_archive="/var/tmp/${archive_basename}"
+echo "Archive: ${archive}"
+
+# Always clean up the relayed copy on the target node, success or failure
+# -- it's only ever a working copy, restored or not.
+cleanup_target_tmp() {
+  if [[ "$keep_backup" -ne 1 ]]; then
+    ssh "$target_target" "rm -f '${target_tmp_archive}'" >/dev/null 2>&1 || true
+  fi
+}
+trap cleanup_target_tmp EXIT
+
+# --- relay the archive from source to target ------------------------------
+echo
+echo "==> Transferring archive to ${target_node}..."
+ssh "$source_target" "cat '${archive}'" | ssh "$target_target" "cat > '${target_tmp_archive}'"
+
+# --- restore on the target node --------------------------------------------
+echo
+echo "==> Restoring as VMID ${new_vmid} on ${target_node} (storage=${target_storage})..."
+if [[ "$kind" == "vm" ]]; then
+  ssh "$target_target" "qmrestore '${target_tmp_archive}' ${new_vmid} --storage ${target_storage} --unique 1"
+else
+  ssh "$target_target" "pct restore ${new_vmid} '${target_tmp_archive}' --storage ${target_storage} --unique 1"
+fi
+
+# --- clean up the source backup now that the restore succeeded -----------
+if [[ "$keep_backup" -ne 1 ]]; then
+  echo
+  echo "==> Deleting backup archive from ${source_node}'s ${source_storage} storage..."
+  ssh "$source_target" "rm -f '${archive}' '${archive}.notes' '${archive}.log'" >/dev/null 2>&1 || true
+fi
+
+echo
+echo "Done. VMID ${new_vmid} (${kind}) is now on ${target_node}, cloned from" \
+  "VMID ${vmid} on ${source_node}."