diff --git a/README.md b/README.md
new file mode 100644
index 0000000..0b5aa61
--- /dev/null
+++ b/README.md
@@ -0,0 +1,188 @@
+# Valheim Server StackScript
+
+A Linode StackScript that turns a freshly created Debian 13 Linode into a
+Valheim dedicated server. Running it as a StackScript means everything happens
+as root during deployment, so no SSH session (and therefore no SSH key) is
+needed to configure the machine.
+
+It does four things, in order:
+
+1. Installs Docker from Debian's own `docker.io` package.
+2. Mounts the pre-existing Valheim volume (this mirrors `voldirections.txt`;
+   `mkfs.ext4` is **not** run because the filesystem already exists).
+3. Creates the persistent `config/` and `data/` directories on the volume.
+4. Starts the Valheim server container with those directories bind-mounted, so
+   worlds, configuration and backups survive destroying and recreating the
+   Linode.
+
+## Instructions
+
+1. Log in to the Linode Cloud Manager and open **StackScripts**.
+2. Click **Create StackScript**.
+3. Set **Label** to something like `valheim-server` and choose **Debian 13**
+   (or "Any") as the **Target Images**.
+4. Paste the code block below into the **Script** editor.
+5. Edit the server settings at the top of the script (name, world, password)
+   before saving.
+6. Leave the **UDF** (User Defined Fields) section empty — the values are
+   hard-coded, so nothing needs to be entered at deploy time.
+7. Click **Save**. The numeric ID of the StackScript appears in the URL and in
+   the StackScript list; copy it.
+8. Put that ID in `create-linode.sh` as the `STACKSCRIPT_ID` value near the top
+   of the file.
+
+After that, `create-linode.sh c <label>` passes the StackScript on the create
+call and the Linode comes up as a running Valheim server with no further steps.
+
+## Where things live on the volume
+
+Everything the container needs to keep is under `/mnt/ValVol202609/valheim`:
+
+| Host path | Container path | Contents |
+| --- | --- | --- |
+| `/mnt/ValVol202609/valheim/config` | `/config` | World saves, `adminlist.txt`, `bannedlist.txt`, `permittedlist.txt`, `backups/` |
+| `/mnt/ValVol202609/valheim/data` | `/opt/valheim` | The ~1 GB downloaded server plus SteamCMD's depot cache |
+
+Mounting `/opt/valheim` as well means a newly created Linode does not have to
+re-download the server from Steam, which saves several minutes per instance.
+The depot cache lives inside that same directory so it stays in sync with the
+installation it belongs to.
+
+Worlds are stored in `config/worlds_local/<WORLD_NAME>/` (older releases used a
+single `<WORLD_NAME>.db`/`.fwl` pair directly in `config/worlds/`). To bring an
+existing world along, copy it into the `worlds_local` directory on the volume
+and set `WORLD_NAME` to match.
+
+## Notes
+
+- **Ports.** The container publishes `2456-2457/udp` (game and query). Linodes
+  have no inbound firewall by default, so nothing else is required. If you add
+  a Cloud Firewall, allow those two UDP ports.
+- **Sizing.** The upstream project recommends a high-clocked 4 core / 8 GB
+  machine, which is exactly `g6-standard-4` — the type `create-linode.sh` uses.
+- **First start.** The container downloads ~1 GB from Steam on first boot and
+  takes several minutes to become joinable.
+- **Admin.** Once the server has started, `config/adminlist.txt` exists on the
+  volume. Put your SteamID64 in it to get in-game admin commands.
+- **Backups.** The container writes hourly world backups to `config/backups/`
+  on the volume and prunes them after 3 days.
+- **Updates.** The container checks for Valheim updates every 15 minutes and
+  restarts the server when one is found, but only while nobody is connected.
+- **Re-running.** The script is safe to run again: the mount and the `fstab`
+  entry are only created if missing, and any previous container is removed
+  before the new one is started.
+
+## StackScript
+
+```bash
+#!/bin/bash
+# Linode StackScript: turn a fresh Debian 13 Linode into a Valheim dedicated
+# server whose worlds, configuration and backups live on the pre-existing
+# Valheim volume. Runs as root during deployment; no SSH access required.
+
+set -euo pipefail
+
+# ---------------------------------------------------------------------------
+# Server settings - edit these before saving the StackScript.
+# ---------------------------------------------------------------------------
+SERVER_NAME="Valheim Server"
+WORLD_NAME="Dedicated"
+# Must be at least 5 characters, otherwise valheim_server.x86_64 refuses to
+# start. Anything saved here is readable by anyone with access to the
+# StackScript, so change it.
+SERVER_PASS="changeme123"
+# true lists the server in the in-game community browser.
+SERVER_PUBLIC="true"
+
+# ---------------------------------------------------------------------------
+# Volume and container settings.
+# ---------------------------------------------------------------------------
+VOLUME_NAME="ValVol202609"
+VOLUME_DEVICE="/dev/disk/by-id/scsi-0Linode_Volume_${VOLUME_NAME}"
+VOLUME_MOUNT="/mnt/${VOLUME_NAME}"
+
+# Everything the container has to keep across Linode rebuilds lives here.
+VALHEIM_DIR="${VOLUME_MOUNT}/valheim"
+CONFIG_DIR="${VALHEIM_DIR}/config"
+DATA_DIR="${VALHEIM_DIR}/data"
+
+CONTAINER_NAME="valheim-server"
+# The upstream project moved to ghcr.io/community-valheim-tools/valheim-server.
+# The Docker Hub image below is still published and can be swapped for it.
+IMAGE="lloesche/valheim-server"
+
+# ---------------------------------------------------------------------------
+# 1. Install Docker.
+# Debian's docker.io package is enough for a single `docker run` and avoids
+# adding a third-party apt repository. ca-certificates is listed explicitly
+# because --no-install-recommends would otherwise skip it and image pulls
+# would fail TLS verification.
+# ---------------------------------------------------------------------------
+export DEBIAN_FRONTEND=noninteractive
+apt-get update
+apt-get install -y --no-install-recommends docker.io ca-certificates docker-cli
+systemctl enable --now docker
+
+# ---------------------------------------------------------------------------
+# 2. Mount the Valheim volume.
+# The volume is attached over the Linode API once the instance is running, so
+# wait for the device to appear. 60 attempts x 5s = 5 minute ceiling.
+# ---------------------------------------------------------------------------
+for _ in $(seq 1 60); do
+  if [ -e "$VOLUME_DEVICE" ]; then
+    break
+  fi
+  echo "Waiting for ${VOLUME_DEVICE} to appear..."
+  sleep 5
+done
+
+if [ ! -e "$VOLUME_DEVICE" ]; then
+  echo "ERROR: ${VOLUME_DEVICE} never appeared. Aborting so that the world is not written to the instance's ephemeral disk." >&2
+  exit 1
+fi
+
+mkdir -p "$VOLUME_MOUNT"
+if ! mountpoint -q "$VOLUME_MOUNT"; then
+  mount "$VOLUME_DEVICE" "$VOLUME_MOUNT"
+fi
+
+# Mount on every boot, without duplicating the line on re-runs. nofail keeps a
+# missing volume from blocking boot; if the volume is not there the mountpoint
+# silently becomes a directory on the instance's own disk, which is why the
+# check above aborts rather than continuing.
+if ! grep -q "$VOLUME_DEVICE" /etc/fstab; then
+  echo "${VOLUME_DEVICE} ${VOLUME_MOUNT} ext4 defaults,noatime,nofail 0 2" >> /etc/fstab
+fi
+
+# ---------------------------------------------------------------------------
+# 3. Create the persistent directories on the volume.
+# ---------------------------------------------------------------------------
+mkdir -p "$CONFIG_DIR" "$DATA_DIR"
+
+# ---------------------------------------------------------------------------
+# 4. Start the Valheim server.
+# --restart unless-stopped brings the server back after a reboot.
+# --stop-timeout 120 gives the server time to save the world on shutdown.
+# --cap-add=sys_nice lets the Steam library raise its own thread priority.
+# ---------------------------------------------------------------------------
+docker rm -f "$CONTAINER_NAME" >/dev/null 2>&1 || true
+
+docker run -d \
+  --name "$CONTAINER_NAME" \
+  --cap-add=sys_nice \
+  --stop-timeout 120 \
+  --restart unless-stopped \
+  -p 2456-2457:2456-2457/udp \
+  -v "${CONFIG_DIR}:/config" \
+  -v "${DATA_DIR}:/opt/valheim" \
+  -e SERVER_NAME="$SERVER_NAME" \
+  -e WORLD_NAME="$WORLD_NAME" \
+  -e SERVER_PASS="$SERVER_PASS" \
+  -e SERVER_PUBLIC="$SERVER_PUBLIC" \
+  "$IMAGE"
+
+echo "Valheim server started."
+echo "The first start downloads ~1GB from Steam and takes several minutes."
+echo "Follow progress with: docker logs -f $CONTAINER_NAME"
+```
+
diff --git a/create-linode.sh b/create-linode.sh
index 0097273..96ab038 100755
--- a/create-linode.sh
+++ b/create-linode.sh
@@ -26,7 +26,8 @@ VOLUME_MOUNT="/mnt/$VOLUME_NAME"
 
 # StackScript that mounts the volume on first boot (see stackscript.md).
 # Enter the numeric StackScript ID manually after creating it in the Linode UI.
-STACKSCRIPT_ID="2225110"
+#STACKSCRIPT_ID="2225110"
+STACKSCRIPT_ID="2225140"
 
 if [[ "$SCRIPT_ACTION" == "" || "$SCRIPT_ACTION" == "--help" || "$SCRIPT_ACTION" == "-?" ]]; then
   echo "Linode helper script: create-linode.sh <action> <label> [args]"
@@ -38,6 +39,7 @@ if [[ "$SCRIPT_ACTION" == "" || "$SCRIPT_ACTION" == "--help" || "$SCRIPT_ACTION"
   echo "         create-linode.sh x <label> get <remote source> <local dest>"
   echo "         create-linode.sh x <label> put <local source> <remote dest>"
   echo "Update record: create-linode.sh a <label> <subdomain>"
+  echo "         (updates the existing A record, creates one if missing)"
   echo "List:    create-linode.sh l"
   echo "         (lists all Linodes, no label needed)"
 fi
@@ -118,6 +120,17 @@ if [[ "$SCRIPT_ACTION" == "d" ]]; then
   INSTANCE_ID=$(curl -s -H "Authorization: Bearer $LINODE_API_KEY" https://api.linode.com/v4/linode/instances | jq '.data[] | select(.label == "'$LINODE_LABEL'") | .id' | sed -e "s/\"//g")
   echo "Destroying ID:$INSTANCE_ID Hit Ctrl-C in the next 10 seconds to cancel."
   sleep 15
+
+  # Shut the Linode down cleanly before deleting it, so systemd stops the
+  # Docker container and the Valheim server gets the chance to save the world
+  # rather than being cut off mid-write.
+  echo "Shutting down ID:$INSTANCE_ID..."
+  curl -s -H "Authorization: Bearer $LINODE_API_KEY" \
+    -X POST https://api.linode.com/v4/linode/instances/$INSTANCE_ID/shutdown | jq .
+
+  # Give the shutdown time to finish before the instance is deleted.
+  sleep 30
+
   curl -s -H "Authorization: Bearer $LINODE_API_KEY" \
     -X DELETE https://api.linode.com/v4/linode/instances/$INSTANCE_ID
   echo "$(date -Iminutes) --- Id:$INSTANCE_ID --- IP:$INSTANCE_IP Destroyed $LINODE_LABEL." >>$LOGFILE
@@ -154,30 +167,54 @@ if [[ "$SCRIPT_ACTION" == "a" ]]; then
   INSTANCE_IP=$(curl -s -H "Authorization: Bearer $LINODE_API_KEY" https://api.linode.com/v4/linode/instances | jq '.data[] | select(.label == "'$LINODE_LABEL'") | .ipv4[]' | sed -e "s/\"//g")
 
   NI_SUBDOMAIN=$3
+  DOMAIN_RECORDS=$(curl -s -H "Authorization: Bearer $LINODE_API_KEY" \
+    https://api.linode.com/v4/domains/$WHICH_DOMAIN/records)
+
   echo "Previous value:"
-  curl -s -H "Authorization: Bearer $LINODE_API_KEY" \
-    https://api.linode.com/v4/domains/$WHICH_DOMAIN/records | jq .
+  echo "$DOMAIN_RECORDS" | jq .
 
   sleep 3
 
+  # Update the A record that already exists for this subdomain rather than
+  # adding another one; a record is only created when there is nothing to
+  # update. DNS names are case-insensitive, so compare them that way.
+  RECORD_IDS=$(echo "$DOMAIN_RECORDS" | jq -r --arg name "$NI_SUBDOMAIN" \
+    '.data[] | select(.type == "A" and ((.name // "") | ascii_downcase) == ($name | ascii_downcase)) | .id')
+  RECORD_ID=$(echo "$RECORD_IDS" | head -n 1)
+  DUPLICATE_IDS=$(echo "$RECORD_IDS" | tail -n +2)
+
   echo "Updating records with ip $INSTANCE_IP..."
 
   #ni7ne:
-  curl -s -H "Content-Type: application/json" \
-    -H "Authorization: Bearer $LINODE_API_KEY" \
-    -X POST -d '{
-	  "type": "A",
-          "name": "'$NI_SUBDOMAIN'",
-          "target": "'$INSTANCE_IP'",
-          "priority": 0,
-          "weight": 0,
-          "port": 0,
-          "service": null,
-          "protocol": null,
-          "ttl_sec": 14400,
-          "tag": null
-        }' \
-    https://api.linode.com/v4/domains/$WHICH_DOMAIN/records | jq .
+  if [[ -n "$RECORD_ID" ]]; then
+    curl -s -H "Content-Type: application/json" \
+      -H "Authorization: Bearer $LINODE_API_KEY" \
+      -X PUT -d '{
+            "type": "A",
+            "name": "'$NI_SUBDOMAIN'",
+            "target": "'$INSTANCE_IP'",
+            "ttl_sec": 14400
+          }' \
+      https://api.linode.com/v4/domains/$WHICH_DOMAIN/records/$RECORD_ID | jq .
+
+    # Duplicates left behind by earlier runs would keep resolving to an old
+    # IP, so remove everything except the record that was just updated.
+    for DUPLICATE_ID in $DUPLICATE_IDS; do
+      echo "Deleting duplicate A record $DUPLICATE_ID for $NI_SUBDOMAIN..."
+      curl -s -H "Authorization: Bearer $LINODE_API_KEY" \
+        -X DELETE https://api.linode.com/v4/domains/$WHICH_DOMAIN/records/$DUPLICATE_ID
+    done
+  else
+    curl -s -H "Content-Type: application/json" \
+      -H "Authorization: Bearer $LINODE_API_KEY" \
+      -X POST -d '{
+            "type": "A",
+            "name": "'$NI_SUBDOMAIN'",
+            "target": "'$INSTANCE_IP'",
+            "ttl_sec": 14400
+          }' \
+      https://api.linode.com/v4/domains/$WHICH_DOMAIN/records | jq .
+  fi
 
   echo "Update complete."
 
diff --git a/stackscript.md b/stackscript.md
deleted file mode 100644
index 33cd4e1..0000000
--- a/stackscript.md
+++ /dev/null
@@ -1,65 +0,0 @@
-# Valheim Volume StackScript
-
-A Linode StackScript that mounts the pre-existing Valheim volume on first boot.
-Running it as a StackScript means the mount happens as root during deployment,
-so no SSH session (and therefore no SSH key) is needed to configure it.
-
-This mirrors the steps in `voldirections.txt`. The filesystem (`mkfs.ext4`) is
-**not** created here, because that step has already been completed on the
-volume; the script only creates the mountpoint, mounts the device, and adds the
-`/etc/fstab` entry.
-
-## Instructions
-
-1. Log in to the Linode Cloud Manager and open **StackScripts**.
-2. Click **Create StackScript**.
-3. Set **Label** to something like `valheim-volume-mount` and choose
-   **Debian 13** (or "Any") as the **Target Images**.
-4. Paste the code block below into the **Script** editor.
-5. Leave the **UDF** (User Defined Fields) section empty — the values are
-   hard-coded, so nothing needs to be entered at deploy time.
-6. Click **Save**. The numeric ID of the StackScript appears in the URL and in
-   the StackScript list; copy it.
-7. Put that ID in `create-linode.sh` as the `STACKSCRIPT_ID` value near the top
-   of the file.
-
-After that, `create-linode.sh c <label>` passes the StackScript on the create
-call and the volume is mounted automatically on first boot.
-
-## StackScript
-
-```bash
-#!/bin/bash
-# Linode StackScript: mount the pre-existing Valheim volume on first boot.
-# Runs as root during deployment; no SSH access required.
-
-set -euo pipefail
-
-# The volume already has an ext4 filesystem (see voldirections.txt), so only
-# the mountpoint, the mount, and the fstab entry are handled here.
-VOLUME_NAME="ValVol202609"
-VOLUME_DEVICE="/dev/disk/by-id/scsi-0Linode_Volume_${VOLUME_NAME}"
-VOLUME_MOUNT="/mnt/${VOLUME_NAME}"
-
-# The volume is attached by the API after deployment starts, so wait for the
-# device to show up before trying to mount it.
-for _ in $(seq 1 30); do
-  [ -e "$VOLUME_DEVICE" ] && break
-  sleep 5
-done
-
-if [ ! -e "$VOLUME_DEVICE" ]; then
-  echo "Volume device ${VOLUME_DEVICE} did not appear; skipping mount." >&2
-  exit 1
-fi
-
-mkdir -p "$VOLUME_MOUNT"
-mount "$VOLUME_DEVICE" "$VOLUME_MOUNT"
-
-# Mount on every boot, without duplicating the line on re-runs.
-grep -q "$VOLUME_DEVICE" /etc/fstab || \
-  echo "${VOLUME_DEVICE} ${VOLUME_MOUNT} ext4 defaults,noatime,nofail 0 2" >> /etc/fstab
-
-echo "Mounted ${VOLUME_DEVICE} at ${VOLUME_MOUNT}."
-```
-