In a nutshell, the installation of Debian on your QNAP TS-41x/TS-42x 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 10 (buster) 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 device, you need the following:
- A QNAP TS-410, TS-410U, TS-412, TS-412U, TS-419P, TS-419P+, TS-419P II, TS-419U, TS-419U+, TS-420, TS-420U, TS-421 or TS-421U.
- An internal SATA disk.
- A network connection.
- Another machine on which you have a telnet and an SSH client. Telnet is included in Linux and Windows. SSH is included in every Linux distribution as OpenSSH and there is PuTTY for Windows.
Note: if you have a QNAP device with 1 GB of RAM (i.e. TS-420U, TS-421 and TS-421U), you have to apply this workaround first.
Making a Backup
You have to make a backup of all the data stored on your QNAP 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 (mtd) partitions. Debian will only modify two flash partitions but it's a good idea to keep a copy of all partitions as you may need them to use the recovery mode. More detailed instructions for making a backup of your flash partitions will be given later.
Starting the Installer
Start your QNAP device and login via SSH. Some time after you start your
machine, you will hear a beep and a bit later you'll hear a longer beep.
Wait for a few more seconds and then connect to the machine via SSH. The
admin and the password is
Once you are logged in, you can save the content of your flash partitions
to a USB stick. Connect a USB stick to your QNAP and wait for the system
to mount it. In my case, it was mounted at
/share/external/sdi1 but you
can find the location with the following command:
mount | grep external /dev/sdi1 on /share/external/sdi1 type vfat [...]
On systems that have never been initialized with the QNAP firmware, the
VFAT module may not be available. If your USB stick does not get mounted,
put it back in your PC and format it with the
Now go to this directory and make a backup of your flash partitions:
cd /share/external/sdi1 cat /dev/mtdblock0 > mtd0 cat /dev/mtdblock1 > mtd1 cat /dev/mtdblock2 > mtd2 cat /dev/mtdblock3 > mtd3 cat /dev/mtdblock4 > mtd4 cat /dev/mtdblock5 > mtd5 cd umount /share/external/sdi1
Disconnect your USB stick from your QNAP, connect it to your PC and to add
mtdX files to your regular backup.
Now you can go ahead and download the installer.
Download and Flash the Installer
In order to download the Debian installer images, issue the following commands:
mkdir /tmp/debian cd /tmp/debian busybox wget http://ftp.debian.org/debian/dists/buster/main/installer-armel/current/images/kirkwood/network-console/qnap/ts-41x/initrd busybox wget http://ftp.debian.org/debian/dists/buster/main/installer-armel/current/images/kirkwood/network-console/qnap/ts-41x/kernel-6281 busybox wget http://ftp.debian.org/debian/dists/buster/main/installer-armel/current/images/kirkwood/network-console/qnap/ts-41x/kernel-6282 busybox wget http://ftp.debian.org/debian/dists/buster/main/installer-armel/current/images/kirkwood/network-console/qnap/ts-41x/flash-debian busybox wget http://ftp.debian.org/debian/dists/buster/main/installer-armel/current/images/kirkwood/network-console/qnap/ts-41x/model
These commands will download the Debian kernel, the installer ramdisk, a file with information about the support QNAP model, and a script to write the kernel and ramdisk to flash. You can now run the script by executing the following command:
Please note that this command will take about three minutes to run. You will see the following on your screen:
Updating MAC address... Your MAC address is 00:08:9B:xx:xx:xx Writing debian-installer to flash... done. Please reboot your QNAP device.
Once the command has completed, you can reboot your QNAP device:
After you have flashed the Debian installer image and restarted your QNAP device, the Debian installer will start. Since the TS-41x/TS-42x 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.
Please note that Ethernet port numeration differs between the QNAP firmware
and Debian. Under Debian,
eth0 is the port marked with "LAN2". On the
TS-419P, this is the lower (and not the upper) connector!
- If your QNAP firmware is configured to use DHCP (the default configuration from QNAP), Debian installer will try to acquire an IP address with DHCP. If you have not initialized your QNAP firmware with QFinder, DHCP will be used. You can use the MAC address of your QNAP device to tell your DHCP server to give out a specific IP address to your machine.
- If you configured a static address in your QNAP firmware, this configuration will be used. However, if your network configuration was incomplete (e.g. IP address or DNS were missing), the installer will use DHCP instead.
- If DHCP is used but your DHCP server does not respond, the device will use the fallback address `192.168.1.100`. If you are unsure what the address of your QNAP is, unplug the Ethernet cable, start the machine again, wait until Debian installer is ready for SSH and then plug the cable back in and connect to this fallback address.
ssh-keygen -f ~/.ssh/known_hosts -R 192.168.1.100
Now connect to the installer (again, replace the address in the
example with the actual IP address of your QNAP) and login as user
installer with the password
The installation itself should be pretty standard and you can follow the installation
guide. The installer knows about the TS-41x/TS-42x 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-41x/TS-42x 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. Your QNAP device will beep when you can connect via
SSH. You will be able to log in your newly created user. (Note that
root logins as disabled by default.)
You should now have a complete Debian system running on your QNAP. You can
apt and other tools to install additional software. The
TS-41x/TS-42x is an ARM based device and the
armel architecture is fully
supported by Debian.
Finally, make sure to read the tips and tricks about running Debian on the QNAP TS-41x/TS-42x.