Detailed Steps:

1. **Connect and Identify the USB Drive:**
    - Plug the USB drive into your Proxmox server.
    - Use the `lsblk` command to list block devices and identify the correct device name (e.g., `/dev/sdb1`, `/dev/sdc1`). Pay attention to the size to ensure you've selected the correct drive. 

Code

```
   lsblk
```

1. **Format the USB Drive:**
    - Use the appropriate command to format the drive with a suitable filesystem. For backups, `ext4` is a good choice. 

Code

```
   mkfs.ext4 /dev/sdX1
```

- Replace `/dev/sdX1` with the actual device name you identified. 
- **Note:** If you are using the drive for Windows VMs, you might need to format it with NTFS. 

1. **Create a Mount Point:**
    - Create a directory where you want to mount the USB drive. 

Code

```
   mkdir /mnt/usb_storage
```

1. **Mount the USB Drive:**
    - Mount the formatted drive to the created mount point. 

Code

```
   mount /dev/sdX1 /mnt/usb_storage
```

1. **Configure Automatic Mounting:**
    - Edit the `/etc/fstab` file to ensure the drive is automatically mounted after a reboot. 

Code

```
   nano /etc/fstab
```

- Add a line similar to the following, replacing the UUID, mount point, and filesystem type as needed: 

Code

```
   UUID=your_uuid /mnt/usb_storage ext4 defaults,noatime,nofail 0 2
```

- To find the UUID, use `lsblk -o +UUID as root`. 
- **Note:** The `nofail` option prevents the system from failing to boot if the drive is not available. 

1. **Add as Proxmox Storage (Optional):**
    - In the Proxmox web interface, navigate to Datacenter > Storage. 
    - Click "Add" and select "Directory". 
    - Configure the storage ID, directory (mount point), and filesystem type (e.g., `ext4`). 
    - You can then use this storage for backups or other purposes.