Disable DHCPv6 on AVM Fritzbox

Posted by Kaya Kupferschmidt • Wednesday, January 25. 2012 • Category: Hardware

If you own a FritzBox router from AVM and use IPv6, this might be interesting for you. If IPv6 is enabled, all clients will get a IPv6 DNS server from the router. Although this might seem to be a nice feature, it creates problems if you run your own DNS server for your local net. All Windows clients first will ask the IPv6 DNS server configured from the FritzBox, and then ask other IPv4 DNS servers. This might be especially bad, if you configured some hostnames in your own DNS server differently for your local net than for the internet (this makes sense if you run some server in your net which is also accessible from the internet). In such situations you really want to get rid of that DNS server announced from the FritzBox.

Unfortunately this is not possible from the GUI, but you can disable DHCPv6 (which is used for announcing) by changing some config file on the FritzBox. So you need to do the following:

  1. Enable telnet via #967.
  2. Login to your FritzBox with telnet fritz.box (or whatever address the FritzBox has in your LAN)
  3. # cd /var/flash
  4. # nvi ar7.cfg
  5. Change the setting dhcpv6lanmode to dhcpv6lanmodeoffstateless
  6. Disable telnet via #968
  7. Reboot the FritzBox

This should completely turn off the DHCPv6 server in the FritzBox.

Serviio DLAN Server on Debian

Posted by Kaya Kupferschmidt • Wednesday, December 28. 2011 • Category: Hardware

If you want to share your media collection (that is music, videos and pictures) in your LAN on multimedia devices like tablets, smartphones, TVs and consoles, you end up using either DLNA or UPnP. Because my devices support DLNA, I decided to give it a try to install a DLNA service on a Debian server. Googling around, I found some different implementations of which Serviio media server looked most primising. Implemented in Java it surely uses some more resources than some native C/C++ implementation, but it offers some nice features like plugins and device profiles. And it offers a pure server implementation without a GUI, which was very important to me for running it on a headless server.

Continue reading "Serviio DLAN Server on Debian"

Add NIS Client Support to ReadyNAS

Posted by Kaya Kupferschmidt • Saturday, February 21. 2009 • Category: Hardware

This guide is about how to setup probably any ReadyNAS device to act as a NIS/YP client. NIS/YP is a protocol that shares account information accross the network. In such an environment it is important that the ReadyNAS knows about all Linux and Windows account, so it can keep access rights on files in sync. If users had different numerical IDs on Linux clients and on the ReadyNAS, all files created from these clients wouldn't beb accessible on Windows machines any more, because the ReadyNAS wouldn't know which account the files belong to.

On Windows there is already a powerful solution, called Active Directory. This is already supported on the ReadyNAS, but there is no support for the corresponding UNIX protocol, which is NIS. Having a central account authority which manages both Windows and Linux accounts via Active Directory and NIS is very helpful in such mixed environments.

Continue reading "Add NIS Client Support to ReadyNAS"

New 6bay ReadyNAS on the way

Posted by Kaya Kupferschmidt • Thursday, January 17. 2008 • Category: Hardware
I really like my ReadyNAS server - small, slick, multifunctional and superb support.

But there are two things missing: more drive bays and a more powerful CPU. But apparently the first point is being addressed with a ReadyNAS Pro device with 6 bays, as seen on CES 2008. I hope, they also spent a more powerful CPU to the device, so it will be able to outperform the Thecus devices. Those are a lot faster, but the firmware and support seems to be really bad.

Can't wait to get my hands on the ReadyNAS Pro!

Why Windows Home Server will be a success

Posted by Kaya Kupferschmidt • Tuesday, January 9. 2007 • Category: Hardware
According to ars technica, Bill Gates showed off his newest product, the Windows Home Server as part of his keynote last Sunday at the CES. The WHS is a small device intended to be the central server for home users for storing their photos, music etc. Paul Thurrot has a small preview of this server and a hardware implementation done by HP (Microsoft only delviers the operating system). On OSNews there has been a debate for the need of such a product.

I predict that the Windows Home Server will be a big success for Microsoft, and I will try to elaborate on the reasons: Nowadays we live in the so called "information age", that is after industrialisation, information is the new driving force in out culture. More and more people have have multiple computers at home (you do not want to know how many I own) and other electronic devices like digital cameras, media players, digital video recorders etc are already standard equipment in many households.

This means that digital content and properties replace traditional values in our life. This also means there is a new need for protection of your personal investments - ten years ago, you could mainly lose your possesions in terms of a physical loss. Nowadays more and more important and valuable data is stored on various computers at each home. This imposes two problems: First you want a centralized storage for all your digital data (photos, movies, music, documents etc), and second you want a secure backup of all your data. Many people become increasingly aware of the first problem, but the second is the really important one. In former times, you only lost part of your values if - for example - a CD got scratches or was stolen.

But nowadays if your harddisc crashes, you probably will lose a lot of irretrievable data like your private email etc. So you wish that you had a backup of all your data, or even better a centralized storage that is protected against hardware faults by some redundancy.

These are just the reasons why a home server makes sense for a lot of people today. One can argue that there are already a lot of good and affordable NAS boxes out there, but most of them are not more than simple NAS boxes (one exception would be Infrants product reportoire) that don't offer comfortable backup utilities or are too complicated for the average user. This is why I see espceially Windows Home Server to be a success - if done right and with the help of Microsofts massive marketing forces.

For me, I probably won't buy a Windows Home Server, because I want something more professional - I want to have a blindingly fast RAID server with tons of storage, support for different file protocols (NFS comes to my mind), although the hardware specs of HPs machien are promising: 1.8 GHz AMD Sempron paired with 512MB of RAM. This should offer twice the performance of Thecus N5200 NAS solution, which is already by far the fastest affordable home NAS out there (although with many firmware limitations and problems).

Why you want ZFS for Linux

Posted by Kaya Kupferschmidt • Saturday, January 6. 2007 • Category: Hardware
Currently I am thinking of replacing my (rather new) ReadyNAS NAS server by a more powerful self-built server. Although the ReadyNAS is a very nice device with very good support from Infrant, it is still too slow for storing all remotely mounted user directories for my Linux and Mac box. Plus I am thinking of using a iSCSI volume for all user directories on my Windows box.

My ideal server would contain an Areca SATA controller with 16 channels and 15 disks in hot-swap carriers running in a RAID-6 plus one or two fast gigabit controllers. So much for the hardware.

But another important aspect is the software of course. Currently I would opt for OpenFiler as operating system for the server. OpenFiler is based on Linux and supports all features I want, except for efficient snapshots. Snapshots are a wonderful thing, they allow to keep an old state of a file-system without the need to do an explicit backup (although one still should backup ones data because of the risk of hardware faults). OpenFiler implements these snapshots using LVM (Logical Volume Manager), which in turn implements snapshots on a Copy-on-Write base. This snapshot implementation has two main drawbacks:
  • You have to allocate space for the snapshot on your disks.

  • The more snapshots you have, the slower gets your system .

And this is exactly the point where Suns filesystem ZFS comes in. ZFS also supports snapshots, but as it seems in a much more efficient way. You do not need to preallocate space for the snapshot and it seems that there is no performance penality by using them. So I'd love to use ZFS together with OpenFiler - but ZFS currently is only available in Solaris with a Linux port under the way. But I guess it will take more time for the Linux port to finish and to be integrated into OpenFiler than I want to wait with my new NAS server.

Snapshots really are the reasons why everyone wants ZFS on Linux. Okay, at least this is my personal top reasons why I want to see it soon. Or a port of OpenFiler to Solaris ;-)