diff --git a/.ansible-lint b/.ansible-lint
index 607c1ab2..c535afc1 100644
--- a/.ansible-lint
+++ b/.ansible-lint
@@ -20,3 +20,8 @@ exclude_paths:
 
 skip_list:
   - var-naming[no-role-prefix]
+
+# The Molecule Vagrant driver injects this module at runtime. The custom create
+# playbook is syntax-checked separately against the exact pinned plugin module.
+mock_modules:
+  - vagrant
diff --git a/.github/scripts/collect-runner-diagnostics.sh b/.github/scripts/collect-runner-diagnostics.sh
index 69f50097..0f6ec12d 100755
--- a/.github/scripts/collect-runner-diagnostics.sh
+++ b/.github/scripts/collect-runner-diagnostics.sh
@@ -26,9 +26,20 @@ run_capture virtualbox-vms VBoxManage list vms
 run_capture virtualbox-running-vms VBoxManage list runningvms
 run_capture virtualbox-disks VBoxManage list hdds
 run_capture virtualbox-hostonlyifs VBoxManage list hostonlyifs
+run_capture virtualbox-groups VBoxManage list groups
 run_capture vagrant-status vagrant global-status
 run_capture molecule-state find "${HOME}/.cache/molecule" -maxdepth 6 -type f -path '*/.vagrant/machines/*/virtualbox/id' -print
 
+scenario_name="${K3S_CI_SCENARIO_NAME:-}"
+if [[ "$scenario_name" =~ ^[A-Za-z0-9_-]+$ ]]; then
+  molecule_state_dir="${HOME}/.cache/molecule/k3s-ansible/${scenario_name}"
+  for log_name in vagrant.out vagrant.err; do
+    if [[ -r "${molecule_state_dir}/${log_name}" ]]; then
+      cp -- "${molecule_state_dir}/${log_name}" "$output_dir/${scenario_name}-${log_name}"
+    fi
+  done
+fi
+
 if [[ -r /etc/vbox/networks.conf ]]; then
   cp -- /etc/vbox/networks.conf "$output_dir/virtualbox-networks.conf"
 fi
diff --git a/.github/scripts/monitor-runner-resources.sh b/.github/scripts/monitor-runner-resources.sh
new file mode 100755
index 00000000..777d6061
--- /dev/null
+++ b/.github/scripts/monitor-runner-resources.sh
@@ -0,0 +1,44 @@
+#!/usr/bin/env bash
+
+set -Eeuo pipefail
+
+output_dir="${1:?output directory is required}"
+interval="${2:-10}"
+[[ "$interval" =~ ^[1-9][0-9]*$ ]] || {
+  printf 'monitor interval must be a positive integer\n' >&2
+  exit 2
+}
+
+mkdir -p -- "$output_dir"
+umask 077
+
+free -h > "$output_dir/memory-before.txt"
+df -h > "$output_dir/disk-before.txt"
+vmstat -w "$interval" > "$output_dir/vmstat.txt" &
+vmstat_pid=$!
+
+iostat_pid=""
+if command -v iostat >/dev/null 2>&1; then
+  iostat -dx "$interval" > "$output_dir/iostat.txt" &
+  iostat_pid=$!
+else
+  printf 'iostat is not installed on this runner\n' > "$output_dir/iostat-unavailable.txt"
+fi
+
+cleanup() {
+  local rc=$?
+  trap - EXIT INT TERM
+  kill "$vmstat_pid" 2>/dev/null || true
+  [[ -z "$iostat_pid" ]] || kill "$iostat_pid" 2>/dev/null || true
+  wait "$vmstat_pid" 2>/dev/null || true
+  [[ -z "$iostat_pid" ]] || wait "$iostat_pid" 2>/dev/null || true
+  free -h > "$output_dir/memory-after.txt"
+  df -h > "$output_dir/disk-after.txt"
+  exit "$rc"
+}
+trap cleanup EXIT INT TERM
+
+while :; do
+  sleep 3600 &
+  wait $!
+done
diff --git a/.github/scripts/prepare-vagrant-box-masters.sh b/.github/scripts/prepare-vagrant-box-masters.sh
new file mode 100755
index 00000000..355405e3
--- /dev/null
+++ b/.github/scripts/prepare-vagrant-box-masters.sh
@@ -0,0 +1,210 @@
+#!/usr/bin/env bash
+
+set -Eeuo pipefail
+
+fail() {
+  printf 'Vagrant box master preparation refused: %s\n' "$1" >&2
+  exit 3
+}
+
+root_contains() {
+  local root="$1"
+  local path="$2"
+  [[ "$path" == "$root"/* ]]
+}
+
+read_machine_value() {
+  local machine_info="$1"
+  local key="$2"
+  awk -F= -v key="$key" '$1 == key {gsub(/"/, "", $2); print $2; exit}' <<< "$machine_info"
+}
+
+read_extra_data() {
+  local uuid="$1"
+  local key="$2"
+  local value
+  value="$(VBoxManage getextradata "$uuid" "$key" 2>/dev/null || true)"
+  [[ "$value" == 'Value: '* ]] || return 1
+  printf '%s\n' "${value#Value: }"
+}
+
+validate_owned_master() {
+  local uuid="$1"
+  local box="$2"
+  local version="$3"
+  local architecture="$4"
+  local machine_info cfg_file cfg_file_real vm_state groups disk_path disk_path_real
+
+  [[ "$uuid" =~ ^[0-9a-fA-F-]{36}$ ]] || return 1
+  machine_info="$(VBoxManage showvminfo "$uuid" --machinereadable 2>/dev/null)" || return 1
+  vm_state="$(read_machine_value "$machine_info" VMState)"
+  groups="$(read_machine_value "$machine_info" groups)"
+  cfg_file="$(read_machine_value "$machine_info" CfgFile)"
+  [[ "$vm_state" == poweroff ]] || return 1
+  [[ ",$groups," == *,/k3s-ansible/box-masters,* ]] || return 1
+  [[ -n "$cfg_file" ]] || return 1
+  cfg_file_real="$(readlink -f -- "$cfg_file" 2>/dev/null || true)"
+  [[ -n "$cfg_file_real" ]] || return 1
+  root_contains "$virtualbox_root_real" "$cfg_file_real" || return 1
+
+  [[ "$(read_extra_data "$uuid" k3s-ansible/owner || true)" == box-master ]] || return 1
+  [[ "$(read_extra_data "$uuid" k3s-ansible/box || true)" == "$box" ]] || return 1
+  [[ "$(read_extra_data "$uuid" k3s-ansible/version || true)" == "$version" ]] || return 1
+  [[ "$(read_extra_data "$uuid" k3s-ansible/architecture || true)" == "$architecture" ]] || return 1
+
+  while IFS= read -r disk_path; do
+    [[ -z "$disk_path" || "$disk_path" == none ]] && continue
+    disk_path_real="$(readlink -f -- "$disk_path" 2>/dev/null || true)"
+    [[ -n "$disk_path_real" ]] || return 1
+    root_contains "$virtualbox_root_real" "$disk_path_real" || return 1
+  done < <(awk -F= '$1 ~ /^(SATA|IDE|SCSI|SAS|VirtioSCSI|NVMe)-[0-9]+-[0-9]+$/ {
+    gsub(/"/, "", $2); print $2
+  }' <<< "$machine_info")
+}
+
+write_prewarm_vagrantfile() {
+  local destination="$1"
+  local box="$2"
+  local version="$3"
+  {
+    printf '%s\n' "Vagrant.configure('2') do |config|"
+    printf '  config.vm.box = "%s"\n' "$box"
+    printf '  config.vm.box_version = "%s"\n' "$version"
+    printf '%s\n' \
+      '  config.vm.synced_folder ".", "/vagrant", disabled: true' \
+      '  config.vm.hostname = "k3s-ansible-box-prewarm"' \
+      '  config.vm.provider "virtualbox" do |virtualbox|' \
+      '    virtualbox.linked_clone = true' \
+      '    virtualbox.memory = 512' \
+      '    virtualbox.cpus = 1' \
+      '  end' \
+      'end'
+  } > "$destination"
+}
+
+cleanup_prewarm() {
+  local rc=$?
+  trap - EXIT
+  if [[ -n "${prewarm_dir:-}" && -d "$prewarm_dir" ]]; then
+    VAGRANT_CWD="$prewarm_dir" vagrant destroy --force >/dev/null 2>&1 || true
+    rm -rf -- "$prewarm_dir"
+  fi
+  exit "$rc"
+}
+
+create_owned_master() {
+  local box="$1"
+  local version="$2"
+  local architecture="$3"
+  local master_id_file="$4"
+  local mapping_file="$5"
+  local uuid machine_info cfg_file cfg_file_real vm_state mapping_tmp
+
+  # A master_id restored from an immutable cache is only a hint. Without the
+  # runner-local ownership record and matching VirtualBox metadata it is not
+  # trusted, adopted, modified, or deleted.
+  rm -f -- "$master_id_file"
+
+  prewarm_dir="$(mktemp -d "${master_root}/prewarm.XXXXXX")"
+  trap cleanup_prewarm EXIT
+  write_prewarm_vagrantfile "$prewarm_dir/Vagrantfile" "$box" "$version"
+
+  printf 'Creating runner-owned linked-clone master for %s %s %s\n' \
+    "$box" "$version" "$architecture"
+  VAGRANT_CWD="$prewarm_dir" vagrant up --provider virtualbox --no-provision
+
+  [[ -r "$master_id_file" ]] || fail "Vagrant did not record a master UUID for $box"
+  uuid="$(tr -d '[:space:]' < "$master_id_file")"
+  [[ "$uuid" =~ ^[0-9a-fA-F-]{36}$ ]] || fail "Vagrant recorded an invalid master UUID for $box"
+
+  machine_info="$(VBoxManage showvminfo "$uuid" --machinereadable 2>/dev/null)" || \
+    fail "Vagrant master $uuid for $box is not registered"
+  vm_state="$(read_machine_value "$machine_info" VMState)"
+  cfg_file="$(read_machine_value "$machine_info" CfgFile)"
+  cfg_file_real="$(readlink -f -- "$cfg_file" 2>/dev/null || true)"
+  [[ "$vm_state" == poweroff ]] || fail "new Vagrant master $uuid is not powered off"
+  if [[ -z "$cfg_file_real" ]] || ! root_contains "$virtualbox_root_real" "$cfg_file_real"; then
+    fail "new Vagrant master $uuid is outside the runner VirtualBox root"
+  fi
+
+  VAGRANT_CWD="$prewarm_dir" vagrant destroy --force
+  VBoxManage modifyvm "$uuid" --groups /k3s-ansible/box-masters
+  VBoxManage setextradata "$uuid" k3s-ansible/owner box-master
+  VBoxManage setextradata "$uuid" k3s-ansible/box "$box"
+  VBoxManage setextradata "$uuid" k3s-ansible/version "$version"
+  VBoxManage setextradata "$uuid" k3s-ansible/architecture "$architecture"
+  validate_owned_master "$uuid" "$box" "$version" "$architecture" || \
+    fail "new Vagrant master $uuid failed ownership validation"
+
+  rm -rf -- "$prewarm_dir"
+  prewarm_dir=""
+  trap - EXIT
+
+  mapping_tmp="${mapping_file}.tmp"
+  printf '%s\n' "$uuid" > "$mapping_tmp"
+  chmod 600 "$mapping_tmp"
+  mv -- "$mapping_tmp" "$mapping_file"
+  printf '%s\n' "$uuid" > "$master_id_file"
+  chmod 600 "$master_id_file"
+  printf 'Created and recorded owned master %s for %s\n' "$uuid" "$box"
+}
+
+repository_root="${K3S_CI_REPOSITORY_ROOT:-$(git rev-parse --show-toplevel)}"
+lock_file="${VAGRANT_BOX_LOCK_FILE:-${repository_root}/.github/vagrant-boxes.lock}"
+vagrant_home="${VAGRANT_HOME:?VAGRANT_HOME must be set}"
+master_root="${K3S_CI_VAGRANT_MASTER_ROOT:-${HOME:?HOME must be set}/.cache/k3s-ci/vagrant-masters}"
+virtualbox_root="${K3S_CI_VIRTUALBOX_ROOT:-${HOME}/VirtualBox VMs}"
+
+[[ -r "$lock_file" ]] || fail "box lock file is missing or unreadable: $lock_file"
+[[ -d "$vagrant_home/boxes" ]] || fail "Vagrant box directory is missing: $vagrant_home/boxes"
+[[ -d "$virtualbox_root" ]] || fail "VirtualBox root is missing: $virtualbox_root"
+
+box_root_real="$(readlink -f -- "$vagrant_home/boxes")"
+virtualbox_root_real="$(readlink -f -- "$virtualbox_root")"
+mkdir -p -- "$master_root"
+chmod 700 "$master_root"
+
+exec 9> "${master_root}/prepare.lock"
+flock 9
+
+lock_entries="$(awk '
+  /^[[:space:]]*#/ || NF == 0 { next }
+  NF != 3 { invalid = 1; next }
+  { print $1 " " $2 " " $3 }
+  END { exit invalid }
+' "$lock_file")" || fail 'invalid Vagrant box lock entry'
+[[ -n "$lock_entries" ]] || fail 'Vagrant box lock is empty'
+
+while read -r box version architecture; do
+  [[ "$box" =~ ^[A-Za-z0-9._-]+/[A-Za-z0-9._-]+$ ]] || fail "invalid box name: $box"
+  [[ "$version" =~ ^[A-Za-z0-9._-]+$ ]] || fail "invalid box version: $version"
+  [[ "$architecture" =~ ^[A-Za-z0-9._-]+$ ]] || fail "invalid box architecture: $architecture"
+
+  box_slug="${box//\//-VAGRANTSLASH-}"
+  record_slug="${box//\//_}-${version}-${architecture}"
+  box_dir="${vagrant_home}/boxes/${box_slug}/${version}/${architecture}/virtualbox"
+  [[ -d "$box_dir" ]] || fail "pinned box is not installed: $box $version $architecture"
+  box_dir_real="$(readlink -f -- "$box_dir")"
+  root_contains "$box_root_real" "$box_dir_real" || fail "box directory is outside VAGRANT_HOME: $box_dir_real"
+
+  master_id_file="${box_dir_real}/master_id"
+  mapping_file="${master_root}/${record_slug}.uuid"
+  uuid=""
+  if [[ -r "$mapping_file" ]]; then
+    uuid="$(tr -d '[:space:]' < "$mapping_file")"
+  fi
+
+  if [[ -n "$uuid" ]] && validate_owned_master "$uuid" "$box" "$version" "$architecture"; then
+    printf '%s\n' "$uuid" > "$master_id_file"
+    chmod 600 "$master_id_file"
+    printf 'Reusing owned master %s for %s %s %s\n' "$uuid" "$box" "$version" "$architecture"
+    continue
+  fi
+
+  if [[ -e "$mapping_file" ]]; then
+    printf 'Owned master record is stale for %s; rebuilding without deleting any VM or disk.\n' "$box"
+  fi
+  create_owned_master "$box" "$version" "$architecture" "$master_id_file" "$mapping_file"
+done <<< "$lock_entries"
+
+printf 'All pinned Vagrant box masters are ready.\n'
diff --git a/.github/scripts/test-fixtures/mock-flock b/.github/scripts/test-fixtures/mock-flock
new file mode 100755
index 00000000..a2828e3a
--- /dev/null
+++ b/.github/scripts/test-fixtures/mock-flock
@@ -0,0 +1,4 @@
+#!/usr/bin/env bash
+
+set -Eeuo pipefail
+[[ "${1:-}" =~ ^[0-9]+$ ]]
diff --git a/.github/scripts/test-fixtures/mock-vagrant b/.github/scripts/test-fixtures/mock-vagrant
new file mode 100755
index 00000000..c9a11c78
--- /dev/null
+++ b/.github/scripts/test-fixtures/mock-vagrant
@@ -0,0 +1,27 @@
+#!/usr/bin/env bash
+
+set -Eeuo pipefail
+
+printf '%s\n' "$*" >> "$MOCK_VAGRANT_LOG"
+case "${1:-}" in
+  up)
+    counter_file="$MOCK_VBOX_STATE/counter"
+    counter=0
+    [[ ! -r "$counter_file" ]] || counter="$(cat "$counter_file")"
+    counter=$((counter + 1))
+    printf '%s\n' "$counter" > "$counter_file"
+    uuid="00000000-0000-4000-8000-$(printf '%012d' "$counter")"
+    vm_dir="$MOCK_VBOX_ROOT/master-$counter"
+    mkdir -p -- "$vm_dir"
+    : > "$vm_dir/master.vbox"
+    : > "$vm_dir/master.vdi"
+    printf '%s\n' \
+      'VMState="poweroff"' \
+      'groups="/"' \
+      "CfgFile=\"$vm_dir/master.vbox\"" \
+      "SATA-0-0=\"$vm_dir/master.vdi\"" > "$MOCK_VBOX_STATE/vm-$uuid"
+    printf '%s\n' "$uuid" > "$MOCK_BOX_DIR/master_id"
+    ;;
+  destroy) ;;
+  *) exit 2 ;;
+esac
diff --git a/.github/scripts/test-fixtures/mock-vboxmanage b/.github/scripts/test-fixtures/mock-vboxmanage
new file mode 100755
index 00000000..dc395cac
--- /dev/null
+++ b/.github/scripts/test-fixtures/mock-vboxmanage
@@ -0,0 +1,40 @@
+#!/usr/bin/env bash
+
+set -Eeuo pipefail
+
+printf '%s\n' "$*" >> "$MOCK_VBOX_LOG"
+command_name="${1:-}"
+uuid="${2:-}"
+
+case "$command_name" in
+  showvminfo)
+    [[ -r "$MOCK_VBOX_STATE/vm-$uuid" ]] || exit 1
+    cat "$MOCK_VBOX_STATE/vm-$uuid"
+    ;;
+  getextradata)
+    key_slug="${3//\//_}"
+    if [[ ! -r "$MOCK_VBOX_STATE/extra-$uuid-$key_slug" ]]; then
+      printf '%s\n' 'No value set!'
+      exit 0
+    fi
+    printf 'Value: '
+    cat "$MOCK_VBOX_STATE/extra-$uuid-$key_slug"
+    ;;
+  modifyvm)
+    [[ "${3:-}" == --groups ]]
+    awk -v groups="${4:-}" '
+      $1 !~ /^groups=/ { print }
+      END { printf "groups=\"%s\"\n", groups }
+    ' "$MOCK_VBOX_STATE/vm-$uuid" > "$MOCK_VBOX_STATE/vm-$uuid.tmp"
+    mv "$MOCK_VBOX_STATE/vm-$uuid.tmp" "$MOCK_VBOX_STATE/vm-$uuid"
+    ;;
+  setextradata)
+    key_slug="${3//\//_}"
+    printf '%s\n' "${4:-}" > "$MOCK_VBOX_STATE/extra-$uuid-$key_slug"
+    ;;
+  unregistervm|closemedium)
+    printf '%s\n' 'destructive VirtualBox command invoked' >&2
+    exit 99
+    ;;
+  *) exit 2 ;;
+esac
diff --git a/.github/scripts/test-prepare-vagrant-box-masters.sh b/.github/scripts/test-prepare-vagrant-box-masters.sh
new file mode 100755
index 00000000..2aaa04d1
--- /dev/null
+++ b/.github/scripts/test-prepare-vagrant-box-masters.sh
@@ -0,0 +1,81 @@
+#!/usr/bin/env bash
+
+set -Eeuo pipefail
+
+repo_root="$(git rev-parse --show-toplevel)"
+fixture="$(mktemp -d)"
+trap 'rm -rf -- "$fixture"' EXIT
+
+mock_bin="$fixture/bin"
+mock_state="$fixture/state"
+mock_home="$fixture/home"
+mock_vagrant_home="$fixture/vagrant-home"
+mock_box_dir="$mock_vagrant_home/boxes/generic-VAGRANTSLASH-ubuntu2204/4.3.12/amd64/virtualbox"
+mock_vbox_root="$mock_home/VirtualBox VMs"
+mock_master_root="$mock_home/.cache/k3s-ci/vagrant-masters"
+lock_file="$fixture/vagrant-boxes.lock"
+mkdir -p -- "$mock_bin" "$mock_state" "$mock_box_dir" "$mock_vbox_root"
+printf '%s\n' 'generic/ubuntu2204 4.3.12 amd64' > "$lock_file"
+ln -s "$repo_root/.github/scripts/test-fixtures/mock-vboxmanage" "$mock_bin/VBoxManage"
+ln -s "$repo_root/.github/scripts/test-fixtures/mock-vagrant" "$mock_bin/vagrant"
+ln -s "$repo_root/.github/scripts/test-fixtures/mock-flock" "$mock_bin/flock"
+
+export PATH="$mock_bin:$PATH"
+export HOME="$mock_home"
+export VAGRANT_HOME="$mock_vagrant_home"
+export VAGRANT_BOX_LOCK_FILE="$lock_file"
+export K3S_CI_REPOSITORY_ROOT="$repo_root"
+export K3S_CI_VAGRANT_MASTER_ROOT="$mock_master_root"
+export K3S_CI_VIRTUALBOX_ROOT="$mock_vbox_root"
+export MOCK_VBOX_STATE="$mock_state"
+export MOCK_VBOX_ROOT="$mock_vbox_root"
+export MOCK_BOX_DIR="$mock_box_dir"
+export MOCK_VBOX_LOG="$fixture/vbox.log"
+export MOCK_VAGRANT_LOG="$fixture/vagrant.log"
+: > "$MOCK_VBOX_LOG"
+: > "$MOCK_VAGRANT_LOG"
+
+unowned_uuid='99999999-9999-4999-8999-999999999999'
+printf '%s\n' "$unowned_uuid" > "$mock_box_dir/master_id"
+
+script="$repo_root/.github/scripts/prepare-vagrant-box-masters.sh"
+first_output="$fixture/first-output"
+second_output="$fixture/second-output"
+third_output="$fixture/third-output"
+
+"$script" > "$first_output"
+mapping_file="$mock_master_root/generic_ubuntu2204-4.3.12-amd64.uuid"
+test -s "$mapping_file"
+cmp -s "$mapping_file" "$mock_box_dir/master_id"
+grep -Fq 'Created and recorded owned master' "$first_output"
+grep -Fq 'modifyvm' "$MOCK_VBOX_LOG"
+grep -Fq 'setextradata' "$MOCK_VBOX_LOG"
+if grep -Fq "$unowned_uuid" "$MOCK_VBOX_LOG"; then
+  printf 'unowned cached master UUID was unexpectedly inspected or modified\n' >&2
+  exit 1
+fi
+if grep -Eq 'unregistervm|closemedium' "$MOCK_VBOX_LOG"; then
+  printf 'master preparation invoked a destructive VirtualBox command\n' >&2
+  exit 1
+fi
+
+: > "$MOCK_VAGRANT_LOG"
+"$script" > "$second_output"
+grep -Fq 'Reusing owned master' "$second_output"
+if grep -Fq 'up ' "$MOCK_VAGRANT_LOG"; then
+  printf 'valid owned master was unexpectedly rebuilt\n' >&2
+  exit 1
+fi
+
+stale_uuid="$(tr -d '[:space:]' < "$mapping_file")"
+rm -f -- "$mock_state/vm-$stale_uuid"
+: > "$MOCK_VAGRANT_LOG"
+"$script" > "$third_output"
+grep -Fq 'rebuilding without deleting any VM or disk' "$third_output"
+grep -Fq 'up ' "$MOCK_VAGRANT_LOG"
+if grep -Eq 'unregistervm|closemedium' "$MOCK_VBOX_LOG"; then
+  printf 'stale master recovery invoked a destructive VirtualBox command\n' >&2
+  exit 1
+fi
+
+printf 'Vagrant box master preparation fixture test passed\n'
diff --git a/.github/scripts/vagrant-up-timed.sh b/.github/scripts/vagrant-up-timed.sh
new file mode 100755
index 00000000..2e0c0139
--- /dev/null
+++ b/.github/scripts/vagrant-up-timed.sh
@@ -0,0 +1,24 @@
+#!/usr/bin/env bash
+
+set -Eeuo pipefail
+
+if (($# < 2)); then
+  printf 'Usage: vagrant-up-timed.sh WORKDIR MACHINE [MACHINE ...]\n' >&2
+  exit 2
+fi
+
+workdir="$1"
+shift
+timing_log="${K3S_CI_CREATE_TIMING_LOG:-${RUNNER_TEMP:-/tmp}/k3s-ci-create-timing.log}"
+mkdir -p -- "${timing_log%/*}"
+
+printf '%s batch-start machines=%s\n' "$(date --iso-8601=ns)" "$*" | tee -a "$timing_log"
+set +e
+VAGRANT_CWD="$workdir" vagrant up "$@" --provider virtualbox --no-provision 2>&1 |
+  while IFS= read -r line; do
+    printf '%s %s\n' "$(date --iso-8601=ns)" "$line"
+  done | tee -a "$timing_log"
+rc=${PIPESTATUS[0]}
+set -e
+printf '%s batch-end rc=%d machines=%s\n' "$(date --iso-8601=ns)" "$rc" "$*" | tee -a "$timing_log"
+exit "$rc"
diff --git a/.github/workflows/cache.yml b/.github/workflows/cache.yml
index fc2cedb9..ef7ce44a 100644
--- a/.github/workflows/cache.yml
+++ b/.github/workflows/cache.yml
@@ -45,7 +45,7 @@ jobs:
           lookup-only: true
           path: |
             .vagrant-home/boxes
-          key: vagrant-boxes-${{ runner.os }}-${{ runner.arch }}-virtualbox-7.2-vagrant-2.4-${{ hashFiles('.github/vagrant-boxes.lock') }} # yamllint disable-line rule:line-length
+          key: vagrant-boxes-${{ runner.name }}-${{ runner.os }}-${{ runner.arch }}-virtualbox-7.2-vagrant-2.4-${{ hashFiles('.github/vagrant-boxes.lock') }} # yamllint disable-line rule:line-length
 
       - name: Download Vagrant boxes for all scenarios
         # An exact hit skips both cache restoration and upstream downloads.
@@ -53,4 +53,5 @@ jobs:
         if: steps.cache-vagrant.outputs.cache-hit != 'true'
         run: |
           ./.github/download-boxes.sh
+          ./.github/scripts/prepare-vagrant-box-masters.sh
           vagrant box list
diff --git a/.github/workflows/test.yml b/.github/workflows/test.yml
index 068f98e9..1f1932d4 100644
--- a/.github/workflows/test.yml
+++ b/.github/workflows/test.yml
@@ -57,9 +57,12 @@ jobs:
         uses: actions/cache/restore@55cc8345863c7cc4c66a329aec7e433d2d1c52a9 # 6.1.0
         with:
           path: .vagrant-home/boxes
-          key: vagrant-boxes-${{ runner.os }}-${{ runner.arch }}-virtualbox-7.2-vagrant-2.4-${{ hashFiles('.github/vagrant-boxes.lock') }} # yamllint disable-line rule:line-length
+          key: vagrant-boxes-${{ runner.name }}-${{ runner.os }}-${{ runner.arch }}-virtualbox-7.2-vagrant-2.4-${{ hashFiles('.github/vagrant-boxes.lock') }} # yamllint disable-line rule:line-length
           fail-on-cache-miss: true
 
+      - name: Prepare runner-owned Vagrant box masters
+        run: ./.github/scripts/prepare-vagrant-box-masters.sh
+
       - name: Install dependencies
         run: |
           echo "::group::Upgrade pip"
@@ -71,7 +74,20 @@ jobs:
           echo "::endgroup::"
 
       - name: Test with molecule
-        run: molecule test --scenario-name ${{ matrix.scenario }}
+        run: |
+          set -Eeuo pipefail
+          resource_dir="${RUNNER_TEMP}/logs/resources/${{ matrix.scenario }}"
+          timing_file="${RUNNER_TEMP}/logs/timing/${{ matrix.scenario }}.txt"
+          mkdir -p -- "${timing_file%/*}"
+          ./.github/scripts/monitor-runner-resources.sh "$resource_dir" 10 &
+          monitor_pid=$!
+          stop_monitor() {
+            kill -TERM "$monitor_pid" 2>/dev/null || true
+            wait "$monitor_pid" 2>/dev/null || true
+          }
+          trap stop_monitor EXIT
+          /usr/bin/time -v -o "$timing_file" \
+            molecule test --scenario-name ${{ matrix.scenario }}
         timeout-minutes: 90
         env:
           ANSIBLE_K3S_LOG_DIR: ${{ runner.temp }}/logs/k3s-ansible/${{ matrix.scenario }}
@@ -79,10 +95,13 @@ jobs:
           ANSIBLE_TIMEOUT: 120
           PY_COLORS: 1
           ANSIBLE_FORCE_COLOR: 1
+          K3S_CI_CREATE_TIMING_LOG: ${{ runner.temp }}/logs/timing/${{ matrix.scenario }}-create.log
 
       - name: Collect runner diagnostics
         if: always()
         run: ./.github/scripts/collect-runner-diagnostics.sh "${RUNNER_TEMP}/logs/runner"
+        env:
+          K3S_CI_SCENARIO_NAME: ${{ matrix.scenario }}
 
       - name: Clean repository-owned resources after testing
         if: always()
diff --git a/.pre-commit-config.yaml b/.pre-commit-config.yaml
index 8fde5469..d8528dfe 100644
--- a/.pre-commit-config.yaml
+++ b/.pre-commit-config.yaml
@@ -50,3 +50,9 @@ repos:
         language: system
         pass_filenames: false
         files: ^\.github/(download-boxes|test-download-boxes)\.sh$|^\.github/vagrant-boxes\.lock$
+      - id: prepare-vagrant-box-masters-test
+        name: Vagrant box master preparation test
+        entry: .github/scripts/test-prepare-vagrant-box-masters.sh
+        language: system
+        pass_filenames: false
+        files: ^\.github/scripts/(prepare-vagrant-box-masters|test-prepare-vagrant-box-masters)\.sh$
diff --git a/molecule/default/create.yml b/molecule/default/create.yml
new file mode 100644
index 00000000..ca1de402
--- /dev/null
+++ b/molecule/default/create.yml
@@ -0,0 +1,87 @@
+---
+- name: Create
+  hosts: localhost
+  connection: local
+  gather_facts: false
+  no_log: "{{ molecule_no_log }}"
+  vars:
+    create_batches:
+      - [control1, control2]
+      - [control3, node1]
+      - [node2]
+  tasks:
+    - name: Verify that bounded batches cover the configured platforms exactly once
+      ansible.builtin.assert:
+        that:
+          - create_batches | flatten | sort == molecule_yml.platforms | map(attribute='name') | sort
+          - create_batches | flatten | length == create_batches | flatten | unique | length
+          - create_batches | map('length') | max <= 2
+        fail_msg: Bounded create batches do not match the configured default platforms.
+
+    - name: Check for existing Vagrant machine state
+      ansible.builtin.stat:
+        path: "{{ molecule_ephemeral_directory }}/.vagrant/machines"
+      register: vagrant_machine_state
+
+    - name: Generate the complete Vagrant configuration for a clean create # noqa fqcn[action]
+      vagrant:
+        instances: "{{ molecule_yml.platforms }}"
+        default_box: "{{ molecule_yml.driver.default_box | default('generic/alpine316') }}"
+        provider_name: "{{ molecule_yml.driver.provider.name | default(omit, true) }}"
+        provision: "{{ molecule_yml.driver.provision | default(omit) }}"
+        cachier: "{{ molecule_yml.driver.cachier | default(omit) }}"
+        parallel: false
+        state: halt
+      when: not vagrant_machine_state.stat.exists
+      changed_when: false
+
+    - name: Start clean Vagrant guests in bounded batches
+      ansible.builtin.command:
+        argv: >-
+          {{
+            [molecule_project_directory + '/.github/scripts/vagrant-up-timed.sh',
+             molecule_ephemeral_directory] + item
+          }}
+      loop: "{{ create_batches }}"
+      loop_control:
+        label: "{{ item | join(', ') }}"
+      when: not vagrant_machine_state.stat.exists
+      changed_when: true
+
+    - name: Reconcile all instances and collect their connection configuration # noqa fqcn[action]
+      vagrant:
+        instances: "{{ molecule_yml.platforms }}"
+        default_box: "{{ molecule_yml.driver.default_box | default('generic/alpine316') }}"
+        provider_name: "{{ molecule_yml.driver.provider.name | default(omit, true) }}"
+        provision: "{{ molecule_yml.driver.provision | default(omit) }}"
+        cachier: "{{ molecule_yml.driver.cachier | default(omit) }}"
+        parallel: false
+        state: up
+      register: server
+      no_log: false
+
+    - name: Populate instance configuration dictionaries
+      ansible.builtin.set_fact:
+        instance_conf_dict:
+          instance: "{{ item.Host }}"
+          address: "{{ item.HostName }}"
+          user: "{{ item.User }}"
+          port: "{{ item.Port }}"
+          identity_file: "{{ item.IdentityFile }}"
+      loop: "{{ server.results }}"
+      register: instance_config_dict
+
+    - name: Convert instance configuration dictionaries to a list
+      ansible.builtin.set_fact:
+        instance_conf: >-
+          {{
+            instance_config_dict.results
+            | map(attribute='ansible_facts.instance_conf_dict')
+            | list
+          }}
+
+    - name: Write Molecule instance configuration
+      ansible.builtin.copy:
+        content: "{{ instance_conf | to_json | from_json | to_yaml }}"
+        dest: "{{ molecule_instance_config }}"
+        mode: "0600"
diff --git a/molecule/default/molecule.yml b/molecule/default/molecule.yml
index 51f418db..2f79fc3c 100644
--- a/molecule/default/molecule.yml
+++ b/molecule/default/molecule.yml
@@ -89,6 +89,7 @@ provisioner:
   env:
     ANSIBLE_VERBOSITY: 1
   playbooks:
+    create: create.yml
     converge: ../resources/converge.yml
     side_effect: ../resources/reset.yml
     verify: ../resources/verify.yml