Git vs. VFAT

June 17th, 2009 Ever copied your Git development tree to a VFAT Filesystem media? Well, if you did then you probably encountered this later:

fatal: Not a git repository

The fix is pretty simple. Git depends on the uppercase file naming of the .git/HEAD file. So if you find it to be lower case then:

mv .git/head .git/HEAD

Dear Git-developers,

why is such an insanity necessary? 0 commentss »

Erlang EEP7 on R13 VM?

April 27th, 2009 I happened to run into Alceste Scalas in the Erlang IRC channel and I asked him about his EEP7 implementation and R13 compatibility. Seems that it will be soon also running on R13 ! 

02:54 < _br_> alceste: nice, good to catch you in the irc. Hey did you happen to get your ffi things running on 
              R13 or R12 ?
02:55 < _br_> alceste: sorry to bother you with this :\
03:10 < alceste> _br_: not yet, but some guy on the erlang-questions mailing list was able to port the patches 
                 and (apparently) make them work
03:10 < alceste> _br_: i'm going to verify it and release updated patches ASAP
03:17 < _br_> alceste: Thank you ! Thats really great :)


Erlang-Questions Mailing list reg. EEP7 on R13A.

Kindness of a random stranger

April 27th, 2009 This weekend something interesting happend to me. I was sitting in McDonalds (I know its unhealty) and eating a Hamburger. The thing costs only 100 yen and for that price its a really cheap and quick supper. It was already quite late so I just wanted quickly to eat something. Well I was sitting there and eating while a elder japanese woman was staring at me. She was maybe 70 or so. So, well she stared at me and I got annoyed for a moment and looked back, smiling. She smiled back and left me alone (looked some other way). I didn't think much of it and continued eating my food. I didn't have anything to drink but I thought, hey, just buy yourself later in the late-night supermarket something.

She got up and went to the counter to buy something leaving her things unattended at the seat. I found that not so good but hey, it's japan and here its a bit safer than in other places around the world. Well, she came back and put a coffee cup with extra milk and sugar in-front of me and said I should drink something.

As you can imagine I was totally baffled and kindly refused. I tried talking to her and seemed she just found it too terrible just eating something and the coffee was so cheap too (120 yen) so no problem. I thanked her and tried to talk to her until her husband came who was totally confused why she was talking to not only a stranger but a foreigner here in japan. Very amusing.

This was the first time a random stranger was kind to me here. I'll not forget that.

Anyway I just wanted to share this interesting, friendly and memorable coincidence with you.

Have a good start into the week!

Remote VNC Connections - Make it easy for users

February 25th, 2009 Do you often need to help friends or family with their Windows system? Something broken on their system and talking them through is just totally impossible? Well probably you like this then. Let them install VNC, e.g. RealVNC. There is a free edition, so make sure they don't install something else.

After that the only thing they need to do is right click on that VNC logo in the Statusbar and select Add remote client. That option is really neat. It lets the user open a reverse connection to an given IP/Port combination, so all that trouble with their firewall or router doesn't matter anymore.

Of course to make things work you need to give them a valid URL or IP combination so that they can connect to. e.g. mydomain.com:5500.

I myself sit behind a NAT'd and routed connection which makes direct connections no good. So I often just SSH tunnel myself to a remote machine for this purpose. The magic to make this happen is that you open two consoles, one for your vnc and another one for your tunnel.

The commands you will need are

The first command basically just opens a vncviewer application in listen mode for inbound connections. The second one is a simple reverse tunnel to the machine at user@mydomain.com where every connection to port 5500 is sent back to my machine. Of course this will only work if you are allowed to do that and if the firewall on mydomain.com is not configured to do something else with :5500 traffic.

Voila! Your user can connect to your connection allowing you to solve their problems more quickly, saving you alot of nerve.

If you are like me and you still like to save more keystrokes, maybe this screen config will come in handy.

% cat bin/screenvncsessionconfig 
screen -t "ssh" 1 ssh -Nv -R 0.0.0.0:5500:localhost:5500 user@mydomain.com
screen -t "vncviewer" 2 vncviewer -listen


For your e.g. Zsh config use this:

% which remotevnc
remotevnc: aliased to ssh-add; screen -S vnc -c /home/br/bin/screenvncsessionconfig


Good Luck !

Digg Architecture

February 18th, 2009 I stumbled across this QCon presentation of Joe Stump who is Lead Architect at Digg. He talks about their architecture and what they did to get the horizontal and vertical scaling done. If you have no idea about how to scale sites from thousands to ten thousand requests a second, never looked into Amazon or EBay scaling and you are not afraid of learning new stuff then this might be very interesting for you.

Further reading:
Further viewing:

Anybody has some other good links?