Martin Michlmayr

QNAP TS-409 from the front

Installing Debian on the QNAP TS-409


In a nutshell, the installation of Debian on your QNAP TS-409 works like this: you use the QNAP firmware to write a Debian installer image to flash. When you restart your device, Debian installer starts and allows you to login via SSH to perform the installation. Debian will be installed to disk and a Debian kernel will be put in flash that will start Debian from disk.

If you follow this procedure, Debian 9 (stretch) will be installed to your SATA disk and the QNAP firmware on disk and in flash will be replaced with Debian. Debian does not install a web interface to configure your machine, although it's possible to install such software. If this is not what you want, please don't proceed with the installation.

Requirements and Preparation

In order to install Debian on a QNAP TS-409, you need the following:

Making a Backup

You have to make a backup of all the data stored on your TS-409 before starting with the installation of Debian since Debian will format the whole disk during the installation. Also, Debian will replace the QNAP firmware in flash, so it's also recommended to make a copy of the flash partitions mtd1, mtd2 and mtd3. Debian will only modify the first two partitions but it's good to keep a copy of these three since they are needed to create a recovery image for the QNAP. More detailed instructions for making a backup of your flash partitions will be given later.

Installing the Recovery Mode

QNAP recently added a recovery mode to the boot loader on QNAP devices that can be used to write a backup image to flash. This is useful in case there are problems during the installation or upgrade of Debian. Since this recovery mode is very new, it's unlikely that it's already installed on your QNAP. Please follow the instructions given on the recovery mode page to install the recovery mode before proceeding with the installation of Debian!

Starting the Installer

There are two slightly different ways of putting the Debian installer on your TS-409 depending on whether you have installed the full QNAP firmware. The QNAP TS-409 only comes with a minimal Linux system in flash and requires an installation to disk for additional functionality. However, this installation requires the QFinder application that is only available for Windows and Mac.

Fortunately, it's possible to put Debian on your QNAP even if you have not used QFinder to initialize the hard drive. First, we will describe how to prepare your TS-409 for the installation of Debian if you have installed the full QNAP firmware with QFinder. Then we will describe how to do it if you haven't.

Preparing Your Fully Initialized System

First of all, you have to activate remote login so you can login to your TS-409 with telnet. Use the QNAP web interface and follow these steps (there is a separate page showing how to activate remote login with some screenshots):

Now that telnet is running, you can connect to your TS-409 with the following command:

telnet 13131

You have to replace with the actual IP address of your TS-409. 13131 is the default port used by the TS-409 for telnet. Use admin as the login name and admin as the password.

Here is a transcript of the login process:

telnet 13131
Connected to
Escape character is '^]'.

NASAC72F3 login: admin
Password: admin (password not displayed)
[~] #

Once you are logged in, you can save the content of your flash partitions to disk with these commands:

cd /share/HDA_DATA/Public
cat /dev/mtdblock1 > mtd1
cat /dev/mtdblock2 > mtd2
cat /dev/mtdblock3 > mtd3

This will put mtd1, mtd2 and mtd3 in the Public share, so you can easily copy them to your PC.

You can skip the next section and download the installer.

Preparing Your Uninitialized System

Putting the Debian installer on an uninitialized QNAP system is pretty similar, but there are two main differences: First, telnet is enabled by default so you don't have to enable it yourself. Second, there is no network share, so you have to copy the backup of the flash content to a USB stick.

Turn on your TS-409 and wait a few minutes until it has started. The machine will make one beep, then there is a brief delay which is followed by three long beeps. The system is ready now and you can connect with telnet. The QNAP device uses DHCP so you have to replace the IP address in the following example with the IP address obtained by your QNAP:

telnet 13131
Connected to
Escape character is '^]'.

NASAC72F3 login: admin
Password: admin (password not displayed)
-sh: id: command not found
-sh: reset: command not found
[~] #

You have to format a USB stick with the ext2 filesystem. This is because the uninitialized QNAP system does not contain the VFAT modules. When you connect the USB stick, it will automatically be mounted on the system. In my case, it was mounted at /share/external/sdi but you can find the location with the following command:

mount | grep external
/dev/sdi1 on /share/external/sdi type ext2 [...]

Now go to this directory and make a backup of your flash partitions:

cd /share/external/sdi
cat /dev/mtdblock1 > mtd1
cat /dev/mtdblock2 > mtd2
cat /dev/mtdblock3 > mtd3
umount /share/external/sdi

Disconnect your USB stick from your TS-409, connect it to your PC and to add the files mtd1, mtd2 and mtd3 to your regular backup.

Now you can go ahead and download the installer.

Download and Flash the Installer

You can download the Debian installer images from the web using the following commands:

cd /tmp
busybox wget
busybox wget
busybox wget
busybox wget

This will download the Debian kernel, the installer ramdisk and a script to write the kernel and ramdisk to flash. You can now run the script by executing the following command:

sh flash-debian

Please note that this command will take about a minute to run. You will see the following on your screen:

Writing debian-installer to flash... done.
Please reboot your QNAP device.

Once the command has completed, you can shut down or reboot your TS-409. When you turn the TS-409 on again, the Debian installer will start.

The Installation

After you have flashed the Debian installer image and restarted your QNAP device, the Debian installer will start. Since the TS-409 does not have any IO device, SSH will be used for the installation. The installer will bring up the network, start the OpenSSH server and you can then connect to the device using SSH. You have to wait a few minutes after starting the system before you can connect. When the installer is ready, the status LED will change to solid green and your device will beep briefly to indicate that you can now login via SSH. (Note: there's currently no beep due to a bug; just wait about 1-2 minutes and connect with SSH.)

Since the TS-409 does not have an LCD, the installer cannot tell you which IP address to connect to or which password to use. With regards to the IP address, the following strategy is used:

Please make sure that the TS-409 is on a local network to which only you have access since the installer uses a very generic password, namely install. The user is installer. Connect to the installer (again, replacing the address in the example with the actual IP address of your TS-409):

ssh installer@

The installation itself should be pretty standard and you can follow the installation guide. The installer knows about the TS-409 and at the end of the installation it will flash a kernel and ramdisk that will automatically boot into Debian. It will also install the qcontrol package that can be used to control the fan, LEDs and beeper on your QNAP device.

Since the TS-409 boots from flash you don't have many limitations as to how you partition your hard drive. You can use LVM and RAID and a number of filesystems.

At the end of the installation, the installer will write the new kernel to flash. Afterwards you will get a confirmation that the installation is complete. Confirm, wait for the installer to finish and once your SSH session terminates, wait a few minutes before you can connect to your newly installed system via SSH. The TS-409 will beep when you can connect via SSH. You will be able to log in as root or your newly created user.

It's possible that you'll get an error during the "make the system bootable" step. If you run into this issue, you can apply a workaround.


You should now have a complete Debian system running on your QNAP. You can use apt-get and other tools to install additional software. The TS-409 is an ARM based device and the armel architecture is fully supported by Debian.

In case you run into any bugs or problems, you may want to check the list of known issues and bugs with Debian on the QNAP TS-409. Finally, make sure to read the tips and tricks about running Debian on the QNAP TS-409.

Go back to my Debian on QNAP TS-409 page.

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