---
title: Create a TrueNAS test vm
publish: true
date: 2026-01-14
tags:
  - guide
description:
---
# TrueNAS Scale VM: Configuring Virtual Disk Serials

## Overview

This guide explains how to assign custom serial numbers to Proxmox virtual disks. 

This is required for TrueNAS Scale to correctly identify disks and form ZFS pools in a virtualized environment.

> [!WARNING] **Test Labs Only**
> Never use virtual disks for production TrueNAS deployments. It prevents ZFS from accessing SMART data and increases data loss risk.

## Prerequisites

* A running PVE node.
* A created TrueNAS Scale VM on your PVE node.
* Basic shell knowledge.

---

## Steps

### Step 1: Locate VM Config

Open an SSH connection to your Proxmox node and identify your TrueNAS VM ID (e.g., `100`).

### Step 2: Add Serial Numbers

Edit the QEMU server configuration file for your VM:

```bash
vi /etc/pve/qemu-server/${TRUENAS_VMID}.conf

```

Locate the lines defining your hard disks (usually starting with `scsi`). Append a unique serial parameter `,serial=XXXX` to the end of each disk line.

**Example Configuration:**

```ini
# Before
scsi1: local-lvm:vm-100-disk-1,discard=on,iothread=1,size=16G,ssd=1
scsi2: local-lvm:vm-100-disk-2,discard=on,iothread=1,size=16G,ssd=1

# After (Ensure every serial string is unique)
scsi1: local-lvm:vm-100-disk-1,discard=on,iothread=1,size=16G,ssd=1,serial=TRUENAS-01
scsi2: local-lvm:vm-100-disk-2,discard=on,iothread=1,size=16G,ssd=1,serial=TRUENAS-02

```

### Step 3: Apply Changes

For these hardware changes to register, you must fully stop and start the VM (a reboot is not sufficient).

```bash
qm stop ${TRUENAS_VMID}
qm start ${TRUENAS_VMID}

```

---

## Verification

Open the Shell inside your running TrueNAS VM and run:

```bash
lsblk -o NAME,SERIAL,SIZE

```

**Expected Output:**

```text
NAME   SERIAL      SIZE
sda    TRUENAS-01  16G
sdb    TRUENAS-02  16G

```

---

## Troubleshooting

### "Disk Serial" or Multipath Errors

**Problem:** TrueNAS complains about duplicate disks or fails to create the pool.
**Solution:** You likely pasted the same serial number for multiple disks. Re-open the `.conf` file and ensure every `serial=...` string is unique.

---

**Created:** 2026-01-14
