The following walkthrough describes how to install Debian on a NETGEAR RN3138 rackmount NAS system.

Required parts

Notes regarding persistent storage on the RN3138

The RN3138 comes from the factory with a high-speed (480Mbps) 256 MB 9-pin (2.00mm pitch) disk-on-module (DOM). The default RN3138 firmware leverages the onboard DOM storage device as a "factory reset" fallback for the original ReadyNAS OS image. This 256 MB DOM is formatted as FAT-16 and only contains a few files. ReadyNAS OS is loaded in RAID across all available disks and not on the DOM.

Prepare the serial data connection

The NETGEAR ReadyNAS RN3138 does not come with a video output port. Serial data pins are located on the rear of the device and must be used for device communication.

1. If applicable, peel off the tape on the rear of the device directly to the left of the "UI" push button. This exposes a 4-pin 2mm pitch header in a 2x2 orientation. The serial port uses 3.3V TTL voltage levels with 115200 8N1 UART signaling.

  ,------- NC (3.3V)
  | ,----- GND
  V V

[ o o ]
[ o o ]

  ^ ^
  | `----- Rx
  `------- Tx

2. Connect one end of each of the female jumper wires to each of the pins as illustrated above.

3. Connect the other end of the female-female jumper cables to the header pins on the USB-TTL adapter as follows:

        | GND  --  GND |
USB-TTL | Rx   --   Tx | RN3138
        | Tx   --   Rx |

Prepare the device for Debian installation

1. Remove all 4 drive bays.

2. In the rear USB3.0 ports, insert both the USB drive containing the Debian installer image and the drive to format and install Debian onto.

3. Launch the serial connection on the host computer:

4. Power on the RN3138 and *immediately* and *repeatedly* begin pressing <delete> on the keyboard to display the BIOS. It may take ~15 seconds of doing this for the BIOS to appear. If nothing appears after 30 seconds or so, try turning off the RN3138 by pressing and holding the front power button, move the USB devices to different ports, and try again. Alternatively press <F1> instead of <delete>, then press <delete> once serial output is achieved.

5. Once the BIOS is reached, use the right arrow key on the keyboard to navigate to "Boot". Select the USB device that contains the minimal Debian installer image. The NAS will continue to boot it.

6. Once you reach the GRUB boot menu showing various Debian install options, use the arrow key to highlight "Start installer" but do not press <Enter>. Kernel arguments must be adjusted to properly handle serial output. Press <e> to edit boot parameters. On the following line (yours may be different):

linux /install/gtk/vmlinuz vga=788 --- quiet
initrd /install/gtk/initrd.gz

Change it to:

linux /install/gtk/vmlinuz vga=off --- quiet console=ttyS0,115200n8
initrd /install/gtk/initrd.gz

...where ttyS0 is the default serial device, and 115200 is the baud rate. The n stands for parity none and the 8 is the number of data bits. Optionally, vga can be changed to vga=off, which makes the video mode error go away, although the installer should start without it.

Press <Ctrl-x> or <F10> to boot.

7. You will then be greeted with a text-only version of the Debian installer. Proceed through this installer like normal.