QNAP added a recovery mode to their devices that can be used when there is a problem with your installation of Debian that renders your device unbootable. The system recovery mode allows you write a recovery image to flash via the network using the TFTP protocol. This pages describes how you can verify whether your device includes the recovery mode, how to upgrade your firmware to a version that includes the recovery mode, how to create recovery images and finally how to use the recovery mode.
Verifying whether your system has the recovery mode
The QNAP recovery mode is relatively new and is not included in QNAP devices that were manufactured prior to 2009. Even if you have a new QNAP device, you should verify whether your firmware includes the recovery mode. You can do this with the following command:
Please compare the first value that is printed with those from the following table to see whether your device has the recovery mode already:
|Checksum||Recovery mode||Build date|
|1009915998||no||Jul 26 2007 - 11:26:33|
|2829080541||no||Feb 19 2008 - 11:13:40|
|45443607||yes||Oct 24 2008 - 17:47:36|
|1135766646||yes||Nov 14 2008 - 17:06:53|
If your device does not have the recovery mode, please read on to see how
you can upgrade your firmware. If the value printed by
cksum is not
listed in this table, please contact me.
Installing the recovery mode
Fully Initialized QNAP System
QNAP provides a page about the recovery mode which tells you exactly how to install the recovery mode. In short, you have to install a QPKG provided by QNAP that will automatically install the recovery mode.
Uninitialized QNAP System
You need a USB stick on which you can store some files. Please put the USB
stick in your PC, download the zip file for your QNAP device from QNAP's recovery mode
page (but ignore the installation instructions from that page). Unzip
the file and copy the
.qpkg file to the USB stick. Now start your QNAP
device and connect the USB stick to it. Login to your QNAP via telnet as
admin user as described in the installation
guide and go into the directory where the USB stick is mounted.
First of all, you should make a backup of your flash partitions using the following commands:
cat /dev/mtdblock1 > mtd1 cat /dev/mtdblock2 > mtd2 cat /dev/mtdblock3 > mtd3
Now you can unpack the QPKG file provided by QNAP:
dd if=QNAP_SystemRecovery_1.0_TS-409.qpkg bs=526 skip=1 | tar xzv
This will create two files:
We are only interested in the latter, which you have to unpack with:
tar xzvf QNAP_SystemRecovery.tgz
Now you can start the actual upgrade process. There are two steps you have
to follow. First of all, you have to update the Linux kernel. Normally,
the Linux kernel is configured so it won't allow you to change
flash partition where the u-boot boot loader is stored. The first step is
therefore to write a Linux kernel to flash that doesn't protect
otherwise you couldn't upgrade u-boot to the new version that includes the
Make sure the checksum of the kernel image matches that listed in the
cksum uImage 3523682680 2000808 uImage cat uImage.cksum 3523682680 2000808 .../uImage
If they match, go ahead and write the kernel to flash:
dd if=uImage of=/dev/mtdblock1
You have to restart your machine now so the new kernel is loaded:
cd umount /share/external/sdi reboot
Once your system has restarted, login as
admin again and go to the
directory where your USB stick is mounted. Then verify the checksum of the
cksum u-boot.bin 2049233834 469608 u-boot.bin cat u-boot.bin.cksum 2049233834 469608 u-boot.bin
If they match, write the new u-boot to flash using the following command. Make sure that you don't interrupt this process and that your QNAP has a good power source. If the process of writing u-boot to flash is interrupted, your QNAP device might no longer boot!
dd if=u-boot.bin of=/dev/mtdblock0
You have successfully upgraded your firmware to a version that includes the recovery mode. You can now go ahead with the installation of Debian.
Creating recovery images
The QNAP recovery image contains a copy of
the kernel partition, ramdisk partition and second ramdisk partition.
The official recovery image is 8 MB, but only the first 7 MB are
actually used during the recovery process: the first 2 MB for
(the Linux kernel), 4 MB for
mtd2 (the ramdisk) and 1 MB for
mtd3 (another ramdisk). The remaining 1 MB are ignored (
mtd5 contain device-specific information and
the u-boot boot loader which is not replaced during recovery).
Since only the first 7 MB are important, we generate a 7 MB recovery image.
Making a recovery image of the QNAP backup
Before installing Debian, you should have made a backup of the QNAP
firmware and have several
mtdX files. You can now make a recovery image
out of the backup with this command:
cat mtd1 mtd2 mtd3 > qnapimg.bin
Making a recovery image from a running system
You can easily make a valid recovery image with the following command:
modprobe mtdblock cat /dev/mtdblock1 /dev/mtdblock2 /dev/mtdblock3 > qnapimg.bin
It is recommended to create periodic recovery images of your flash, so you have a recovery image in case something goes wrong.
Making a recovery image containing the Debian installer
If you want to make a QNAP recovery image containing the Debian installer, you can follow these steps. First of all, download the initrd and kernel for the installer. You now have to pad the kernel so it is the right size:
dd if=kernel of=kernel.pad ibs=2097152 conv=sync
Finally, you can create a recovery image:
cat kernel.pad initrd mtd3 > qnapimg.bin
Note that the
mtd3 file in this command refers to the backup you created
earlier (before the installation).
Using the recovery mode
In case your Debian system no longer boots after a system upgrade, you can use the QNAP system recovery mode to restore a previous image, an image of the Debian installer, or the QNAP firmware.
The recovery mode will request a recovery image by TFTP from a server on
your network. The QNAP will use the IP address
192.168.0.10 and will
request a file called
qnapimg.bin from the server with the address
192.168.0.11. These addresses cannot be configured.
You can activate the recovery mode by pressing the reset button on the back of your QNAP for about 10 seconds. I suggest you press the reset button and keep it pressed, and then turn on your QNAP device. After about 10 seconds, you will hear two short beeps. Your QNAP will now request a recovery image via TFTP. When it has obtained the recovery image and written it to flash, your QNAP will make one long beep and restart.
More information about the recovery mode can be found on QNAP's System Recovery Mode page.