So, now that the installation is done, let's take stock. First of all what's missing as compared to the stock QNAP firmware? The first and most obvious omission is the web interface. If you want to administer this NAS now, you'll be using a command line.
But if you prefer configuration via a web-interface, you can easily install something like Webmin. Figure 2 shows Webmin running on my TS-209 after I used standard Debian commands to install it. (You can find the basic commands here if you need them and the Webmin Debian installation instructions here.)
Figure 2: Webmin on Debian
You can see in the network configuration screenshot in Figure 2 above that Debian brought up an IPV6 interface in addition to a standard IPV4 interface. You can also see a column of options off to the left that is quite extensive and that's a general theme here. It may be a bit more work, but when you're not relying on a vendor to narrow down your options, you have a lot more flexibility to do what you really need, with the downside being additional complexity.
With this distribution, you're a bit on the bleeding edge with respect to some features that were present in the QNAP firmware. First there is currently no support for DMA mode in the disk drivers, although a Marvell engineer is apparently working it on. This means your disk performance will be a bit less than under QNAP's firmware.
Second, while there is fan control via the qcontrol command, you can't yet set it up so that the speed is temperature-based. That means a bit more noise than you may have had before. And you're on your own for setting up the system so that your disks will spin down when not in use. I've seen a procedure for setting this up. But it's nowhere as easy as the menu-based configuration in the QNAP firmware (for example, you get to decide what it means for the system to be idle).
QNAP included Twonkyvision, a commercial UPnP AV media server, in their firmware. But that won't be in your new Debian system. If you need a media server, you can install MediaTomb as an open source replacement. Figure 3 shows the web interface of MediaTomb running on my TS-209 Pro after I installed it using apt-get install mediatomb from the command line.
Figure 3: MediaTomb on Debian
There are also little things missing that you might be used to under the standard QNAP firmware. For example, when you plug in a USB drive, don't expect it to be automatically mounted. If that's the behavior you want, you'll need something like autofs, (installed via apt-get install autofs). Then once it's installed, you'll have to set up the particular behavior you want by editing the configuration files.
The LED and buzzer behavior may also not be what you expect. But you can change those via the qcontrol command. Execute man qcontrol for options on how to use it.
But enough about what's missing, what's available? Lots. Estimates vary, but there may be over 20,000 installable packages available for loading on a Debian system. Want to do some development? I issued an apt-get install build-essential command and a few minutes later I had a complete native tool-chain on the box, which I verified by writing a little "Hello world" program in C (Figure 4 ).
Figure 4: Debian development via the command-line
Interested in python, php or postgresql? They're all a simple install command away. Want to use some exotic USB peripheral? I counted 69 USB drivers available on my stock Debian system. And of course, since this is Linux, you can always install the kernel source tree, hack away and install your own kernel and drivers. That's what it's all about. The freedom to tinker and make the box do what you want instead of what the manufacturer decided was needed.