“ZFS is really the final word in filesystems. With a feature set longer than this tutorial, it can take a while to master. You can set many more options per dataset, enable disk usage quotes and much more. Once you’ve used it and seen the benefits, you’ll probably never want to use anything else. Hopefully this has been helpful to get you on your way to becoming a FreeBSD ZFS master.”
Some might know AmbiLight – a great invention by Philips that projects colored light around a TV screen based upon the contents shown. It’s a great addition to a TV but naturally only available with Philips TV sets.
Not anymore. There are several open-source projects that allow you to build your very own AmbiLight clone. I’ve built one using a 50-LEDs WS2801 stripe, a 5V/10A power supply, a RaspberryPi, and the BobLight integration in RaspBMC (this is a nice XBMC distribution for the Pi).
“Boblight is a collection of tools for driving lights connected to an external controller.
Its main purpose is to create light effects from an external input, such as a video stream (desktop capture, video player, tv card), an audio stream (jack, alsa), or user input (lirc, http). Boblight uses a client/server model, where clients are responsible for translating an external input to light data, and boblightd is responsible for translating the light data into commands for external light controllers.”
The hardware to start with looks like this:
I’ve fitted some heat-sinks to the Pi since the additional load of controlling 50 LEDs will add a little bit of additional CPU usage which is desperately needed when playing Full HD High-Bitrate content.
The puzzle pieces need to be put together as described by the very good AdaFruit diagram:
As you can see the Pi is powered directly through the GPIO pins. You’re not going to use the MicroUSB or the USB ports to power the Pi. It’s important that you keep the cables between the Pi and the LEDs as short as possible. When I added longer / unshielded cables everything went flickering. You do not want that – so short cables it is :-)
When you look at aboves picture closely you will find a CO and DO on the PCB of the LED. on the other side of the PCB there’s a CI and DI. Guess what: That means Clock IN and Clock OUT and Data IN and Data OUT. Don’t be mistaken by the adapter cables the LED stripes comes with. My Output socket looked damn close to something I thought was an Input socket. If nothing seems to work on the first trials – you’re holding it wrong! Don’t let the adapters fitted by the manufacturer mislead you.
Depending on the manufacturer of your particular LED stripe there are layouts different from the above image possible. Since RaspBMC is bundled with Boblight already you want to use something that is compatible with Boblight. Something that allows Boblight to control each LED in color and brightness separately.
I opted for WS2801 equipped LEDs. This pretty much means that each LED sits on it’s own WS2801 chip and that chip takes commands for color and brightness. There are other options as well – I hear that LDP8806 chips also work with Boblight.
My power supply got a little big to beefy – 10 Amps is plenty. I originally planned to have 100 LEDs on that single TV. Each LED at full white brightness would consume 60mA – which brings us to 6Amps for a 100 – add to that the 2 Amps for the PI and you’re at 8A. So 10A was the choice.
To connect to the Pi GPIO Pins I used simple jumper wires. After a little bit of boblightd compilation on a vanilla Raspbian SD card (how-to here). Please note that with current RaspBMC versions you do not need to compile Boblight yourself – I’ve just taken for debugging purposes as clean Raspbian Image and compiled it myself to do some boblight-constant tests. Boblight-constant is a tool that comes with Boblight which allows you to set all LEDs to one color.
If everything is right, it should look like this:
Now everything depends on how your LED stripes look like and how your TVs backside looks like. I wanted to fit my setup to a 42″ Samsung TV. This one already is fitted with a Ultra-Slim Wall mount which makes it pretty much sitting flat on the wall like a picture. I wanted the LEDs to sit right on the TVs back and I figured that cable channels when cut would do the job pretty nicely.
To get RaspBMC working with your setup the only things you need to do are:
- Enable Boblight support in the Applications / RaspBMC tool
- Login to your RaspBMC Pi through SSH with the user pi password raspberry and copy your boblight.conf file to /etc/boblight.conf.
The configuration file can be obtained from the various tutorials that deal with the boblight configuration. You can choose the hard way to create a configuration or a rather easy one by using the boblight configuration tool.
I’ve used the tool :-)
Now if everything went right you don’t have flickering, the TV is on the wall and you can watch movies and what-not with beautiful light effects around your TV screen. If you need to test your set-up to tweak it a bit more, go with this or this.
Source 1: http://en.wikipedia.org/wiki/Ambilight
Source 2: http://www.raspberrypi.org/
Source 3: https://code.google.com/p/boblight/
Source 4: http://www.raspbmc.com/
Source 5: http://learn.adafruit.com/light-painting-with-raspberry-pi/hardware
Source 6: How-To-Compile-Boblight
Source 7: Boblight Config Generator
Source 8: Boblight Windows Config Creation Tool
Source 9: Test-Video 1
Source 10: Test-Video 2
Having fun with hardware is a good way to learn about the machines which soon will become our new overlords. With this pretty interesting presentation you can dive deep into what a CPU does and how it can be exploited to run code by not running it.
“Trust Analysis, i.e. determining that a system will not execute some class of computations, typically assumes that all computation is captured by an instruction trace. We show that powerful computation on x86 processors is possible without executing any CPU instructions. We demonstrate a Turing-complete execution environment driven solely by the IA32 architecture’s interrupt handling and memory translation tables, in which the processor is trapped in a series of page faults and double faults, without ever successfully dispatching any instructions. The “hard-wired” logic of handling these faults is used to perform arithmetic and logic primitives, as well as memory reads and writes. This mechanism can also perform branches and loops if the memory is set up and mapped just right. We discuss the lessons of this execution model for future trustworthy architectures.”
SDR – or Software Defined Radio is relatively cheap and fun way to dive deeper into radio communication.
“Software-defined radio (SDR) is a radio communication system where components that have been typically implemented in hardware (e.g. mixers, filters, amplifiers, modulators/demodulators, detectors, etc.) are instead implemented by means of software on a personal computer or embedded system. While the concept of SDR is not new, the rapidly evolving capabilities of digital electronics render practical many processes which used to be only theoretically possible.” (Wikipedia)
So with cheap hardware it’s possible to receive radio transmissions on all sorts of frequencies and modulations. Since everything after the actual “receiving stuff”-phase happens in software the things you can do are sort of limitless.
Now what about the relatively cheap factor? – The hardware you’re going to need to start with this is a DVB-T USB stick widely available for about 25 Euro. The important feature you’re going to look for is that it comes with a Realtek RTL2832U chip.
“The RTL2832U is a high-performance DVB-T COFDM demodulator that supports a USB 2.0 interface. The RTL2832U complies with NorDig Unified 1.0.3, D-Book 5.0, and EN300 744 (ETSI Specification). It supports 2K or 8K mode with 6, 7, and 8MHz bandwidth. Modulation parameters, e.g., code rate, and guard interval, are automatically detected.
The RTL2832U supports tuners at IF (Intermediate Frequency, 36.125MHz), low-IF (4.57MHz), or Zero-IF output using a 28.8MHz crystal, and includes FM/DAB/DAB+ Radio Support. Embedded with an advanced ADC (Analog-to-Digital Converter), the RTL2832U features high stability in portable reception.” (RealTek)
You’ll find this chip in all sorts of cheap DVB-T USB sticks like this one:
To use the hardware directly you can use open source software which comes pre-packaged with several important/widely used demodulator moduls like AM/FM. Gqrx SDR is available for all sorts of operating systems and comes with a nice user interface to control your SDR hardware.
The neat idea about SDR is that you, depending on the capabilities of your SDR hardware, are not only tuned into one specific frequency but a whole spectrum several Mhz wide. With my device I get roughly a full 2 Mhz wide spectrum out of the device allowing me to see several FM stations on one spectrum diagram and tune into them individually using the demodulators:
The above screenshot shows the OS X version of Gqrx tuned into an FM station. You can clearly see the 3 stations that I can receive in that Mhz range. One very strong signal, one very weak and one sort of in the middle. By just clicking there the SDR tool decodes this portion of the data stream / spectrum and you can listen to a FM radio station.
Of course – since those DVB-T sticks come with a wide spectrum useable – mine comes with an Elonics E4000 tuner which allows me to receive – more or less useable – 53 Mhz to 2188 Mhz (with a gap from 1095 to 1248 Mhz).
Whatever your hardware can do can be tested by using the rtl_test tool:
root@berry:~# rtl_test -t
Found 1 device(s):
0: Terratec T Stick PLUS
Using device 0: Terratec T Stick PLUS
Found Elonics E4000 tuner
Supported gain values (14): -1.0 1.5 4.0 6.5 9.0 11.5 14.0 16.5 19.0 21.5 24.0 29.0 34.0 42.0
Benchmarking E4000 PLL…
[E4K] PLL not locked for 52000000 Hz!
[E4K] PLL not locked for 2189000000 Hz!
[E4K] PLL not locked for 1095000000 Hz!
[E4K] PLL not locked for 1248000000 Hz!
E4K range: 53 to 2188 MHz
E4K L-band gap: 1095 to 1248 MHz
Interestingly when you plug the USB stick into an Raspberry Pi and you follow some instructions you can use the Raspberry Pi as an SDR server allowing you to place it on the attic while still sitting comfortably at your computer downstairs to have better reception.
If you want to upgrade your experience with more professional hardware – and in fact if you got a sender license – you can take a look at the HackRF project which currently is creating a highly sophisticated SDR hardware+software solution:
Source 1: http://www.realtek.com.tw/products/productsView.aspx?Langid=1&PFid=35&Level=4&Conn=3&ProdID=257
Source 2: http://gqrx.dk/
Source 3: www.hamradioscience.com/raspberry-pi-as-remote-server-for-rtl2832u-sdr/
Source 4: http://ossmann.blogspot.de/2012/06/introducing-hackrf.html
Source 5: https://github.com/mossmann/hackrf
Last year in June I wrote about the concept of a ubiquitous status display of the business in every office. Especially for development and operations it’s pretty important to have important measurements, status codes and project information in front of them all the time.
Back then I already wrote about the Panic status board which gives a great looking example of a status display. Now there is a software from the company Panic which offers anyone the ability to create such a status board. It’s for iOS and looks awesome!
And once again some smart people put their heads together and came up with something that will revolutionize your world. Well it’s ‘just’ home automation but indeed it looks very very promising. Especially the human-machine interface through speech recognition. First of all let’s start with a short introductory video:
“CastleOS is an integrated software suite for controlling the automation equipment in your home – an operating system for your castle, if you will. The first piece of the suite is what we call the “Core Service” – it acts as the central controller for the whole system. This runs on any relatively recent Windows computer (or more specifically, the computer that has an Insteon PLM or USB stick plugged in to it), and creates a network connection to both your home automation devices, and the second piece of the integrated suite – the remote access apps like the HTML5 app, Kinect voice control app, and future Android/iOS apps.” (from the CastleOS page)
So it’s said to be an all-in-one system that controls power-outlets and devices through it’s core service and offering the option to add Kinect based speech recognition to say things like “Computer, Lights!”.
Unfortunately it comes with quite high and hard requirements when it comes to hardware it’s compatible with. A kinect possible exists in your household but I doubt that you got the Insteon hardware to control out devices with.
That seems to be the main problem of all current home automation solutions – you just have to have the according hardware to use them. It’s not quite possible to use anything and everything in a standardized way. Maybe it’s time to have a “home plug’n’play” specification set-up for all hard- and software vendors to follow?
Source 1: http://www.castleos.com
So first a small video to get an idea what I am implementing right now:
- to draw svg in a human-controllable
- to draw those nice gauges
- an animated HTML5 canvas odometer
I plan to add a lot more – like for swiping gestures. So this will be – just like h.a.c.s – a continuous project. Since I switched to OS X entirely at home I use the great Coda2 to write and debug the code. It helps a lot to have two browser set-up because for some reason I still not feel that well with the WebKit Web Inspector.
Another great feature of Coda2 is the AirPreview – which means it will preview your current page in the editor on an iOS device running DietCoda – oh how I love those automations.
Wikipedia describes latency this way:
“Latency is a measure of time delay experienced in a system, the precise definition of which depends on the system and the time being measured. In communications, the lower limit of latency is determined by the medium being used for communications. In reliable two-way communication systems, latency limits the maximum rate that information can be transmitted, as there is often a limit on the amount of information that is “in-flight” at any one moment. In the field of human-machine interaction, perceptible latency has a strong effect on user satisfaction and usability.” (Wikipedia)
Given that it’s quite important for any developer to know his numbers. Since latency has a huge impact on how software should be architected it’s important to keep that in mind:
So after I wrote about the great fileserver expansion plans I thought I give a short update on the progress:
Isn’t technology great when it brings families closer together, even when they are thousand miles apart?
Home automation does not only mean that you are going to flip some switches and sensor away in every imaginable way. It also means creativity. And being creative with the functionalities at hand is really what makes home automation so interesting.
It’s those creative ways that adds use to the nerdy home automation switches and sensors. It’s what adds practicality.
Good Night Lamp is such a creative solution that makes use of home automation hardware and the internet. To understand the concept, watch a video:
“The Good Night Lamp is a family of connected lamps that lets you communicate the act of coming back home to your loved ones, remotely.”
Well I don’t know if it really needs specialized hardware like those Good Night Lamp products. But certainly if you have some sensory and the ability to flip switches it is fairly easy to come up with workflows and things that should happen when the circumstances are right. In fact I do not believe in highly specialized products like a single-purpose lamp. But I do believe, if those lamps are connected to a network and if you can access them through some sort of API, that those types of products will pave the way to a connected world we only know from science fiction yet.
Another good solution to this is the long promised IP capable light bulb. Engineers were using the “light bulb with an ip adress” as an example for IPv6 for years now. And it seems that the time has come when we really want to assign an ip adress to every lightbulb in our home.
LIFX is a good start concept and in a couple of months there will be more manufacturers who are offering networked light bulb solutions.
The first signs of the upcoming camera board for the raspberry pi are showing. During the Electronica 2012 fair RS showed the board to the public for the first time.
Since it’s going to be a 25 Euro add-on for the Pi the specification is quite impressive. The OmniVision OV5647 is used as the Image Sensor – it’s bigger brother is used in iPhone 4. OmniVision says:
“The OV5647 is OmniVision’s first 5-megapixel CMOS image sensor built on proprietary 1.4-micron OmniBSI™ backside illumination pixel architecture. OmniBSI enables the OV5647 to deliver 5-megapixel photography and high frame rate 720p/60 high-definition (HD) video capture in an industry standard camera module size of 8.5 x 8.5 x ≤5 mm, making it an ideal solution for the main stream mobile phone market.
The superior pixel performance of the OV5647 enables 720p and 1080p HD video at 30 fps with complete user control over formatting and output data transfer. Additionally, the 720p/60 HD video is captured in full field of view (FOV) with 2 x 2 binning to double the sensitivity and improve SNR. The post binning re-sampling filter helps minimize spatial and aliasing artifacts to provide superior image quality.
OmniBSI technology offers significant performance benefits over front-side illumination technology, such as increased sensitivity per unit area, improved quantum efficiency, reduced crosstalk and photo response non-uniformity, which all contribute to significant improvements in image quality and color reproduction. Additionally, OmniVision CMOS image sensors use proprietary sensor technology to improve image quality by reducing or eliminating common lighting/electrical sources of image contamination, such as fixed pattern noise and smearing to produce a clean, fully stable color image.
The low power OV5647 supports a digital video parallel port or high-speed two-lane MIPI interface, and provides full frame, windowed or binned 10-bit images in RAW RGB format. It offers all required automatic image control functions, including automatic exposure control, automatic white balance, automatic band filter, automatic 50/60 Hz luminance detection, and automatic black level calibration.”
That sensor delivers RAW RGB Imagery to the RaspberryPi through the onboard camera connector interface:
And the part that impressed me the most is that that 5 Megapixel sensor delivers it’s raw data stream and it gets h264 compressed directly within the GPU of the Raspberry Pi. 30 frames per second 1080p without noticeable CPU load – how does that sound? – Not bad for a 50 Euro setup!
In times when mobile phone cameras produce pictures of 2 MBytes each and decent DSLR cameras produce pictures in the range of more than 20 Mbytes each – not speaking of the various sensors around the house the question of how all of this is going to be stored is an interesting one.
Prices for mass storage is dropping for years and sized of hard disks are getting bigger and bigger. 3 Tbyte drives are fairly cheap now. Cheap enough to consider serious redundancy even for home use.
Having that home automation hobby and having very specific needs when it comes to home entertainment or even watching TV (we don’t watch live-tv…) we have a relatively huge demand for storage space. That way we are already storing over 10 Tbyte of data, fully encrypted, redundant and backed-up.
Our file server infrastructure grew with the needs over the years.
It started way back in 2003 when I set-up the first fileserver for my apartment back then. It was a fairly huge 19 inch case with 5 hard disks (100 Gbyte each). This machine was filled in 2005 and needed replacement.
We’re in IDE land back then. Because the system hardware died on me due to a power surge all the disks and a new mainboard were seated in a new case with room for a lot of disks.
One interesting detail might be that I consistently used Windows Server for that purpose.
The machine always wasn’t just a fileserver. It was smtp, imap, nntp and media server all the time. That lead to a growing demand of CPU and memory resources. It started with an 800 Mhz AMD Athlon (which died quickly) and for the next years to come I used a 2.8 Ghz Intel Pentium 4. Everything started with Windows Server 2003 – bought in the Microsoft Store when I was a Microsoft employee.
Diskspace demand kept growing and in 2009 a new case, new mainboard + memory and new disks where due.
Since 2009 a Core4Quad Q9550 with 2.8 Ghz and 16 Gbyte of Memory is the heart of our fileserver. Since we’re frequently live-transcoding video streams to feed iPads and iPhones around the house that machine has plenty of grunt to feed the demand. We can have 2 iPhones and 2 iPads playing 720p content without getting stutters. Back in 2009 we also switched to a mixed IDE and SATA setup as you can see in the picture:
Plenty of room when the new case arrived – it was getting crowded just 2 years later in 2011. Every seat was taken – which means 13 disks are in that case and 1 attached through USB.
That adds up to more than 16 Tbyte of raw storage. In 2011 we also upgraded to Windows Server 2008. We never lost a bit with that operating system, not under the heaviest load and even through serious hardware malfunctions. A lot of disks of those 13 died throughout the years: Almost 1 every 2 months was replaced – most of them through extended waranties – of course we have a spare always ready to take the place. Only one time I had to rush to a store to get a replacement drive when two disks failed short after each other. That’s why there’s that 2 Tbyte drive in the 1.5 Tbyte compound…
So it’s getting full again. Since that case isn’t really holding more disks and replacing them is getting harder because of the tight fit the idea was born to now add a bigger case but to just add a NAS/SAN which holds between 6 to 8 disks at once, comes with it’s own redundancy management and exports one big iSCSI volume.
That said a network card was added to the fileserver and a QNAP TS-859 Pro+ 8-bay appliance was bought. This one is a shiny black device which uses less power then an aditional case with extra cpu and memory would have use and after calculating through a number of combinations it’s even the cheapest solution for an 8 drive set-up.
After some intensive testing it seems that the iSCSI approach is the most robust one. Since I am just done with testing the appliance the next step is to buy drives. So stay tuned!
Finally another Raspberry Pi with two brand new cases arrived. Finally I’ve got a case for two of my PIs – hurray!
Update: Andreas salso got his pi and case – he has more pictures.
Do you know what happens during the push of the power button and typing your log-in information inside of your computer? No? You should. At least from a software side. Not that it is necessary to use a computer. But in order to understand what this wonderful machine does and why.
For those teaching and learning purposes the Raspberry Pi is a perfect device. It’s cheap and now there is a course you can take online which shows you – starting from the very beginning – how to get the device up and running and how to make it do what you like. And that’s without installing an operating system. You are about to write your very own.
“This website is here to guide you through the process of developing very basic operating systems on the Raspberry Pi! This website is aimed at people aged 16 and upwards, although younger readers may still find some of it accessible, particularly with assistance. More lessons may be added to this course in time.”
It appeared to me that I stopped working with a decent keyboard since I moved completely to Macs at home. I was using the keyboards the machine came with and not always does Apple deliver the best possible keyboard for the money.
So I tried to turn back to my trusty IBM PS/2 Model M last week and I had to find out that somehow the actively powered USB to PS2 adapter I had is got lost. A passive one just doesn’t cut it and the keyboard does not work at all.
I remembered that in 2006 I wrote about a back-then-new keyboard that resembled the fantastic Model M. Voilá! They even worked on their keyboards since 2006 and improved them :-)
A little bit more than 6 years after writing first about the product I got me a “das Keyboard Ultimate S EU”.
First verdict: It is awesome!
It’s expensive, that’s true. But if just feels right typing on it. I can see me writing a lot of stuff for longer periods on that keyboard :-)
Just a couple of days ago – after a waiting time of more than half a year – my personal raspberry pi board arrived. Fantastic!
It’s small. Oh yes, it’s very very small.
What is the Raspberry Pi you may ask:
“The Raspberry Pi is a credit-card sized computer that plugs into your TV and a keyboard. It’s a capable little PC which can be used for many of the things that your desktop PC does, like spreadsheets, word-processing and games. It also plays high-definition video. We want to see it being used by kids all over the world to learn programming.”
For under 40 Euro you get a huge choice of I/O interfaces like USB, Ethernet, HDMI, Audio and Multi Purpose IO pins you can play with if you’re into hardware hacking. This small card is running a fully blown linux and because it has a dedicated graphics core which can hardware decode and encode 1080p h264 it’s definitely a good choice for a home mediacenter (yes, XBMC runs on it.)
It draws so little power that you could use solar panels to power it. It’s all open and sourced and I will use it for a couple of things in the household. Like a cheap Airplay node. Or a more intelligent sensor node for home automation. This thing seriously rocks – finally a device to play with – with reasonable horse-power.
There are many things which are underestimated when team leads think about their team and possible actions to drive progress.
One of those things is that a team needs information to maintain and gain velocity. You cannot expect everyone to know just out of the blue what is important and in which direction everything is moving. To let everyone know and to develop that direction it’s important to share information as much as possible. It’s important to give everyone access to the information necessary to make a better job.
That’s why we had a build monitor at sones. We had a tool that displayed the current status of our build servers to all developers. Everytime someone committed a change, those build servers got this commit, built it and tested it with automated tests. The status of that could be seen by all developers as things happened.
So within seconds everyone could see if his commit did break something. Even better: Everyone could see. Everyone cared that the build needed to be working, that tests needed to pass. It was everyones job to do the housekeeping. When we switched from Team Foundation Server to GIT and Jenkins this status display needed to be replaced – you could immediately tell that things went from good to not-so-good in terms of build stability and automated testing.
Today I had the opportunity to take a tour of the Thomann logistics center. Standing in the support department I had this in front of me:
There were like 6 big status screens displaying incoming call status of the day, sales figures and other statistics important to those who work there. It’s a very important and integrated way to keep information flowing.
Since I am with Rakuten I thought about having a new status board set-up for my team. Something that might be inspired by the awesome status board which panic has built:
Since in addition to sones there are a lot of more things to track and handle (code, deployment, operations, overall numbers) I think such a status board will be of invaluable worth for the team.
Two weeks ago I had read an article about a “replacement for papernotes” product called “Boogie Board”. The company behind the product claims to replace paper with the bold slogan of “say goodby to paper”.
Well what is it? Basically it’s a liquid crystal display without the logic to adress specific pixels. So think of it like taking the liquid crystal part and leaving out all the transistors and logic to actually display something. Then add a pen or even your finger nail and you can “write” on that display – what’s happening is that obviously the crystals get pushed aside and the background of the “display” shines through – this background is white so when you write on the boogie board everything is white on black…
The only button on the tablet is named “erase” – and that’s what the button does: the whole display flashes two times, one white, and then black and everything is back to where we started. You cannot save. You just press erase and start over. It’s truly a replacement for post-it-notes…
Of course there’s a battery inside, and it’s said to hold for tens of thousands of erases. You cannot change the battery when it’s empty, but on the other hand this gadget is less than 30 Euros and it does look like you can break it up and try your best to exchange the battery yourself. Since the battery isn’t needed to display anything I don’t think I will run out of juice just yet.
Irgendwie werden es auch privat immer immer mehr Daten – mit immer zunehmender Geschwindigkeit… Alle paar Jahre tausche ich bei uns im Haushalt die Festplatten/Speicherlösung komplett aus – was zwar immer wieder mal eine Investitions bedeutet, gleichzeitig aber auch dafür sorgt dass Daten nicht irgendwelchen ungünstigen mechanischen, chemischen oder magnetischen Effekten zum Opfer fallen… Ja so etwa alle zwei Jahre wird alles einmal umkopiert… Das dauerte beim letzten Mal zwar gut eine Woche, aber naja so ist das eben…
Aus vielerlei Grund haben wir auch für einen Haushalt recht viel Bedarf an Speicherplatz – teilweise wohl auch weil meine Frau Photographin ist – aber ich als “werf-nix-weg”-Typ werd da auch einen guten Anteil dran haben…
Herr über alle unsere Festplatten (kein Witz, die Rechner bei uns haben ihre Festplatten eigentlich nur um booten zu können) ist seit jeher ein einzelner Rechner welcher ebenso alle paar Jahre komplett ausgetauscht wird. Dieser Rechner verwaltet im Moment zwischen 12-15 Festplatten verschiedener Größe – Hauptarbeit wird zur Zeit durch drei separate (gewachsene) RAID-5 Volumes erledigt…
Nebenbei: Nein ich kann/will da kein RAID-6 fahren ohne entweder Linux zu verwenden (was aus verschiedenen Gründen nicht geht) oder einen Hardware-Controller zu verwenden, was nach einschlägigen Erfahrungen querbeet durch alle möglichen Hardware RAID Controller ausfällt.
Dem ganzen Festplattenstapel liegt dann ein Standard-PC mit Windows Server 2008 zugrunde – zum einen weil ich so eine Lizenz noch herumliegen hatte und zum anderen weil ich in über 10 Jahren File-Server Erfahrungen sammeln noch nie auch nur ein Byte unter Windows verloren habe. Zusätzlich habe ich einen riesigen Haufen Software welche Windows-only ist ud sozusagen ständig laufen muss um Sinn zu machen (Mail-Server Puffer, Newsserver Mirror, Musik und Video Streaming Server, Medienbibliothek, Videorekorder,…
Diese drei großen RAID Volumes schnappt sich dann Truecrypt und ver- und entschlüsselt zuverlässig vor sich hin – im Endeffekt gibt es kein Byte Daten im Haushalt welches nicht verschlüsselt wäre. Gut für uns.
So ein RAID verhindert nun ja aber nicht dass dennoch oben genannte ungünstige Effekte eintreten und man mal eine oder mehrere Defekte zu beklagen hat. Im Normalfall tauscht man die defekte Festplatte, resynct das RAID und alles funktioniert weiter ohne dass man Daten verloren hätte. Allerdings ist das ja kein Backup. Das ist nur eine erste Absicherung gegen mögliche Defekte.
Getreu folgendem kurzen Musikstück:
… ist ein RAID eben kein Backup. Backups erledigt bei mir eine Sammlung von Scripten welche jeweils in festen Abständen Vollbackups und Differenz-Backups erstellt. Da kommt dann ein Haufen 1 Gbyte großer Dateien raus welche dann anschliessend per RSync in mühevoller (und dank funktionierendem QoS unbemerkt) Arbeit außer Haus geschafft werden. Die Komplett-Backups dauern aufgrund der großen Menge einfach ewig lang und lassen sich recht einfach dadurch beschleunigen dass man sozusagen das Backup physisch auf einer externen Festplatte zum Server trägt…die Differenz-Backups sind dann meist immer recht flott durchgelaufen. Speicherplatz im Internet wird ja auch immer billiger und so haben wir auch immer ein gutes Off-Site Backup unserer Daten…
Für Windows gibt es neben den üblichen Cygwin Ports von rsync auch eine gute GUI Version namens DeltaCopy. Das Ding kopiert zuverlässig und auch wenn mal der DSL Router rebootet oder hängt nimmt er selbständig die Kopierarbeit wieder auf sobald Netz wieder verfügbar ist.
Damit DeltaCopy seine Daten irgendwo abladen kann wird auf der Gegenstelle natürlich ein rsync Server vorrausgesetzt. Die Konfiguration eines solchen ist nicht sonderlich kompliziert – im Grunde muss man nur rsync installieren und die rsyncd.conf Datei anpassen. Zusätzlich dazu muss man eine Konfigurationsdatei anlegen in welchem nach dem Schema “Benutzername:Passwort” entsprechend die Nutzeraccounts angegeben werden – das wars eigentlich schon. Rsync ist sehr robust und vor allem auch gut für geringere Bandbreiten geeignet. Wenn sich an einer Datei nur wenige Bytes geändert haben müssen auch nur die geänderten Bytes übertragen werden.
Source 1: http://www.speichergurke.de
Source 2: http://www.aboutmyip.com/AboutMyXApp/DeltaCopy.jsp
Source 3: http://de.wikipedia.org/wiki/Rsync
So finally after years and years of hope and nerdy ideas I am able to hold a tablet device in my own hands and it’s not only as good as Picards tablet was back in that great “Star Trek: Next Generation” series, it’s better.
Of course I had to import that particular iPad from the U.S. (thanks Alex!) – actually it was the first time I imported something that expensive. Beside some fun with the shipping company everything went fine. Since Apple just announced to delay the launch of the iPad in Europe for a month it’s nice to have a gadget just a few weeks after it was available in the U.S.
Oh what a nice n3rd toy this would be. Rumors say it will be available soon for under $30. And for those who right now think: “What the hell is this?” – This is a coffee mug in the shape of a quite expensive canon lens. In fact I already heard of that idea more than a year ago and wrote about it here. At this time there were only hopes that it would be produced.
Since sones will be at some community events, conferences and trade shows this year we thought it might be a good idea to have some hardware to document these events.
Since we wanted to have video and we did not want to cope with the rather complex subject of DSLRs we bought a full-hd-camcorder.
This is just beautiful:
Mission accomplished. I successfully talked a co-worker, who needed to buy a new car, into buying a gadget-packed BMW 1 series.
He calls it his “cluster on 4 wheels” – because obviously there is some processing “horse-power” in this machine :-)
May he always have a safe ride!
Source 1: http://blog.ahzf.de/index.php/2009/09/21/mein-cluster-hat-vier-rader/
I’ve run into several problems while trying to install the current 8.1 version of the APC PowerChute Business Edition.
Basically I get this error message when I am trying to install it:
So you can simply not install this version of PowerChute on this machine – OR you could go here and follow the link to the Download of the 8.0 version of the software. This will start the setup with this screen:
Great! Just get the “old” version and use it.
Source 1: APC PowerChute and VMWare
I ran into some strange problems with a notebook that leaded to sound drop-outs or things like sluggish UI and HDD performance. So I tried almost everything troubleshootig the problem. That worked for some problems but there are occasions when I want to have a more systematic approach to those kinds of hardware / driver related problems.
One tool that can help to find hardware / driver problems is the DPC Latency Checker. This tool measures and displays the latency of your system. All you have to do is watch as the measurements scroll by and remove / disable one device after another from your machine. As soon as the latency turns green again there’s a high probability that the device you removed last has a problem of some kind.
On my machine everything is in the greens now – after some BIOS and driver updates. If your system has some issues you would see something like that:
(courtesy of Gnawgnu’s Realm)
Last week I upgraded my iPod touch to an iPhone… well actually I got a new iPhone 3GS aside the iPod.
It’s a fast device – even noticeably faster than the 2nd gen iPod Touch. It’s got almost the same battery life like the touch for me and it was a plug-and-play experience to use it the first time.
What I wasn’t expecting is that the smooth experience suddenly came to a stop when I tried to plug the iPhone into my car – just where the iPod touch did the job for about 5 months (including that the touch got charged by the car along the way).
With the iPhone I got two error messages simultaneously:
“Charging not supported by this accessory”
“This accessory is not supported by iPhone”
Damn you Apple! What’s the problem? There’s a standard USB port which powered 2,5 inch hard disk drives previously and the iPhone just states that it cannot be charged with this accessory (e.g. the car).
On the other hand everything else just works as it was working with the iPod. I can browse my music library on the iDrive I can listen to music – everything works, beside those two error messages and the not-charging iPhone. Thank you Apple B-) Maybe I need to up-grayed my car too?
Today we had a great meeting with SciEngines. These guys offer a great platform for everything that needs massive parallelism and IO bandwidth scalability. They even brought a small copacobana cluster to our headquater.
I always asked myself when this particular notebook will fail. Almost everybody I know who got this notebook got his mainboard replaced in the last year. Now it seems that it’s time for my Latitude to get a new set of chips.
It crashed while I was using it and since that it only boots up like this:
Oh I looked up which graphic chip that actually is. It’s a NVidia NVS135 chip – not like I thought the NVS160 which is embedded in my current generation latitude. Thank god I got 3 year repair and replacement….
So it’s been some days with the new Mediacenter Setup. And all I can say is: Oh boy that is some serious cool setup. I wouldn’t want to chance anything beside adding a new Sound System (>5.1 FTW!).
The Display itself is thinner than thought:
I strongly recommend the Mac + Plex + Full HD display setup. Even if you don’t get any HD content from your cable provider you can live-stream or download HD content through the different provider plugins inside Plex. The plugin infrastructure with the built-in “App Store” is just great.
Since Plex is a XBMC based Mediacenter software you have tons of information scrapers regarding series and movies. So you’re eventually huge collection gets indexed and presented in a way you would not get from any other Mediacenter. You get pictures, movie posters, descriptions and many more just by automatic indexing your collection.
Needless to say that HD content is something different. I only had some HD content on normal computer displays in the last years – having it now huge and sharp is different – better.
BTW: It’s on the floor right now because my wife couldn’t decide until now which tv-stand would suffice…
Finally we got a TV set. Since Samsung announced new LED based sets we ordered a 46 inch tv. It was delivered today (yesterday the Mac mini which will drive the mediacenter arrived). I only had a short test-run scanning for cable stations… so more of that in the following days – especially more of the mediacenter configuration.
Source: Samsung UE46B6000