diff --git a/bin/lib/onboard.js b/bin/lib/onboard.js
index be320ad8fa..650f572bd2 100644
--- a/bin/lib/onboard.js
+++ b/bin/lib/onboard.js
@@ -12,6 +12,7 @@ const nim = require("./nim");
 const policies = require("./policies");
 const HOST_GATEWAY_URL = "http://host.openshell.internal";
 const EXPERIMENTAL = process.env.NEMOCLAW_EXPERIMENTAL === "1";
+const DEFAULT_GATEWAY_NAME = "nemoclaw";
 
 // ── Helpers ──────────────────────────────────────────────────────
 
@@ -21,6 +22,10 @@ function step(n, total, msg) {
   console.log(`  ${"─".repeat(50)}`);
 }
 
+function shellQuote(value) {
+  return `'${String(value).replace(/'/g, `'\\''`)}'`;
+}
+
 function isDockerRunning() {
   try {
     runCapture("docker info", { ignoreError: false });
@@ -82,22 +87,78 @@ async function preflight() {
   return gpu;
 }
 
+/**
+ * Fully tear down the gateway including Docker volumes that can cause
+ * "Corrupted cluster state" on subsequent runs.
+ */
+function gatewayVolumeCandidates(gatewayName = DEFAULT_GATEWAY_NAME) {
+  return [`openshell-cluster-${gatewayName}`];
+}
+
+function cleanupGatewayVolumes(runFn = run, gatewayName = DEFAULT_GATEWAY_NAME) {
+  const removedVolumes = [];
+  const failedVolumes = [];
+
+  for (const volumeName of gatewayVolumeCandidates(gatewayName)) {
+    const inspectResult = runFn(`docker volume inspect ${shellQuote(volumeName)} >/dev/null 2>&1`, {
+      ignoreError: true,
+      stdio: "ignore",
+    });
+    if (inspectResult.status !== 0) continue;
+
+    const removeResult = runFn(`docker volume rm -f ${shellQuote(volumeName)} >/dev/null 2>&1`, {
+      ignoreError: true,
+      stdio: "ignore",
+    });
+    if (removeResult.status === 0) removedVolumes.push(volumeName);
+    else failedVolumes.push(volumeName);
+  }
+
+  return { removedVolumes, failedVolumes };
+}
+
+function manualGatewayVolumeCleanupCommand(volumeNames) {
+  return `docker volume rm -f ${volumeNames.map(shellQuote).join(" ")}`;
+}
+
+function reportGatewayCleanupResult(cleanupResult) {
+  if (cleanupResult.failedVolumes.length > 0) {
+    console.error("  Automatic cleanup could not remove all stale Docker volumes.");
+    console.error(`  Run: ${manualGatewayVolumeCleanupCommand(cleanupResult.failedVolumes)}`);
+    return;
+  }
+
+  console.error("  Stale state removed. Please rerun the installer.");
+}
+
+function destroyGateway(runFn = run, gatewayName = DEFAULT_GATEWAY_NAME) {
+  runFn(`openshell gateway destroy -g ${gatewayName} 2>/dev/null || true`, { ignoreError: true });
+  return cleanupGatewayVolumes(runFn, gatewayName);
+}
+
 // ── Step 2: Gateway ──────────────────────────────────────────────
 
 async function startGateway(gpu) {
   step(2, 7, "Starting OpenShell gateway");
 
-  // Destroy old gateway
-  run("openshell gateway destroy -g nemoclaw 2>/dev/null || true", { ignoreError: true });
+  // Destroy old gateway and clean up any leftover Docker state from previous failures
+  destroyGateway();
 
-  const gwArgs = ["--name", "nemoclaw"];
+  const gwArgs = ["--name", DEFAULT_GATEWAY_NAME];
   // Do NOT pass --gpu here. On DGX Spark (and most GPU hosts), inference is
   // routed through a host-side provider (Ollama, vLLM, or cloud API) — the
   // sandbox itself does not need direct GPU access. Passing --gpu causes
   // FailedPrecondition errors when the gateway's k3s device plugin cannot
   // allocate GPUs. See: https://build.nvidia.com/spark/nemoclaw/instructions
 
-  run(`openshell gateway start ${gwArgs.join(" ")}`, { ignoreError: false });
+  const startResult = run(`openshell gateway start ${gwArgs.join(" ")}`, { ignoreError: true });
+  if (startResult.status !== 0) {
+    console.error("  Gateway failed to start. Cleaning up stale state...");
+    const cleanupResult = destroyGateway();
+    reportGatewayCleanupResult(cleanupResult);
+    console.error("  If the error persists, run: openshell gateway info");
+    process.exit(1);
+  }
 
   // Verify health
   for (let i = 0; i < 5; i++) {
@@ -107,7 +168,10 @@ async function startGateway(gpu) {
       break;
     }
     if (i === 4) {
-      console.error("  Gateway failed to start. Run: openshell gateway info");
+      console.error("  Gateway health check failed. Cleaning up...");
+      const cleanupResult = destroyGateway();
+      reportGatewayCleanupResult(cleanupResult);
+      console.error("  If the error persists, run: openshell gateway info");
       process.exit(1);
     }
     require("child_process").spawnSync("sleep", ["2"]);
@@ -501,4 +565,11 @@ async function onboard() {
   printDashboard(sandboxName, model, provider);
 }
 
-module.exports = { onboard };
+module.exports = {
+  cleanupGatewayVolumes,
+  destroyGateway,
+  gatewayVolumeCandidates,
+  manualGatewayVolumeCleanupCommand,
+  onboard,
+  reportGatewayCleanupResult,
+};
diff --git a/test/onboard.test.js b/test/onboard.test.js
new file mode 100644
index 0000000000..57605ab074
--- /dev/null
+++ b/test/onboard.test.js
@@ -0,0 +1,53 @@
+// SPDX-FileCopyrightText: Copyright (c) 2026 NVIDIA CORPORATION & AFFILIATES. All rights reserved.
+// SPDX-License-Identifier: Apache-2.0
+
+const { describe, it } = require("node:test");
+const assert = require("node:assert/strict");
+const {
+  cleanupGatewayVolumes,
+  gatewayVolumeCandidates,
+  manualGatewayVolumeCleanupCommand,
+} = require("../bin/lib/onboard");
+
+describe("gateway cleanup helpers", () => {
+  it("uses the known OpenShell volume name for the default gateway", () => {
+    assert.deepEqual(gatewayVolumeCandidates(), ["openshell-cluster-nemoclaw"]);
+  });
+
+  it("removes known gateway volumes when they exist", () => {
+    const commands = [];
+    const runFn = (cmd) => {
+      commands.push(cmd);
+      if (cmd.includes("docker volume inspect")) return { status: 0 };
+      if (cmd.includes("docker volume rm -f")) return { status: 0 };
+      return { status: 1 };
+    };
+
+    const result = cleanupGatewayVolumes(runFn);
+
+    assert.deepEqual(result, {
+      removedVolumes: ["openshell-cluster-nemoclaw"],
+      failedVolumes: [],
+    });
+    assert.equal(commands.length, 2);
+  });
+
+  it("returns the exact manual recovery command when automatic cleanup fails", () => {
+    const runFn = (cmd) => {
+      if (cmd.includes("docker volume inspect")) return { status: 0 };
+      if (cmd.includes("docker volume rm -f")) return { status: 1 };
+      return { status: 1 };
+    };
+
+    const result = cleanupGatewayVolumes(runFn);
+
+    assert.deepEqual(result, {
+      removedVolumes: [],
+      failedVolumes: ["openshell-cluster-nemoclaw"],
+    });
+    assert.equal(
+      manualGatewayVolumeCleanupCommand(result.failedVolumes),
+      "docker volume rm -f 'openshell-cluster-nemoclaw'"
+    );
+  });
+});