Reset Ubuntu password without knowing the root password

Reset Ubuntu password without knowing the root password

# 🔑 Proxmox VE: How to Reset Forgotten Ubuntu VM/LXC Password

This guide covers the methods for resetting a forgotten user or root password for an Ubuntu guest system installed on Proxmox Virtual Environment (PVE).

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## 🛑 Method 1: For Linux Containers (LXC) - Easiest

If your Ubuntu guest is an **LXC Container**, you can change the password directly from the Proxmox Host shell as the container shares the kernel.

1.  Log in to your **Proxmox Host** via SSH or use the PVE Web GUI's **Shell** tab.
2.  Run the following commands, replacing `101` with your container's ID and `your_username` with the user you want to reset.

    ```bash
    # 1. Enter the running container environment
    pct enter 101

    # 2. Change the password for a specific user
    passwd your_username

    # 3. Enter the new password twice when prompted
    # 4. Exit the container shell
    exit
    ```

3.  You can now log in to the container using the new password.

---

## 🛠️ Method 2: For Virtual Machines (VM) - Standard GRUB Edit

This is the standard procedure for resetting a password in a full Ubuntu VM by using the **GRUB boot loader** to access a root shell.

### 1. Access the GRUB Menu
1.  Go to the **Console** tab of your Ubuntu VM in the Proxmox GUI.
2.  Click **Reboot**.
3.  **Immediately** press and hold the **`Shift`** key (or tap **`Esc`** repeatedly) as the VM starts to force the display of the GRUB boot menu.

### 2. Edit Boot Parameters
1.  Use the arrow keys to highlight the default **Ubuntu** boot entry.
2.  Press the **`e`** key to edit the boot configuration.
3.  Scroll down to the long line that starts with **`linux`** (or `linuxefi`).
4.  Find the section containing the boot mode (e.g., `ro quiet splash` or `ro maybe-ubiquity`).
5.  **DELETE** this section and replace it with:
    ```bash
    rw init=/bin/bash
    ```

    **Example of the change (Do NOT delete the `linux` line, only edit the bolded part):**

    | Before (Original Line End) | After (Edited Line End) |
    | :--- | :--- |
    | `... root=UUID=xxxx ro quiet splash` | `... root=UUID=xxxx` **`rw init=/bin/bash`** |

6.  Press **`Ctrl` + `X`** or **`F10`** to boot the system using the modified command.

### 3. Reset the Password
The VM will boot directly into a root command line shell (`#`).

1.  Reset the password for your user (replace `your_username`):
    ```bash
    passwd your_username
    ```
2.  Enter and confirm your new password when prompted.

### 4. Reboot
Once the password has been successfully reset, reboot the system to apply the changes permanently:

```bash
exec /sbin/init