linux
Change Keyboard Shortcuts in Gnome-Shell (Gnome 3)
I really love Gnome 3 and its Shell, but I almost went nuts on this. It really took me a while to finally figure this out. To make a really short blog post even shorter: Use dconf-editor (from package dconf-tools) and go to org.gnome.desktop.wm.keybindings. There you have it. Why would I want to change keyboard [...]
“Internet slow” on Ubuntu Karmic Koala (9.10)
“Internet slow” means actually “DNS slow”. After upgrading to Ubuntu 9.10 I experienced a strange and very annoying lag in DNS resolution. Running dig in a shell worked like a charm. But Firefox, Synaptic and everything else was hanging at DNS resolution. To make a long story short (you probably read a lot of forum [...]
collectd + drraw.cgi – zoom into your graphs like you used to with cacti
I fell in love with collectd and drraw.cgi (a front-end to collectd). This combination is great: Fast, simple and yet sufficient. But there was one thing I missed in drraw that I loved in cacti: Zooming. (This is how it looks like in cacti) So I went on and hacked it into drraw.cgi using jQuery. [...]
Linux: Executables on a Samba/CIFS Share
Just a quick note: Don’t mount a cifs share with flag directio if you want to execute binaries that reside on that share. Otherwise you will get the following error: <command>: cannot execute binary file Took me 2 hours to find out.
Hadoop and Linux kernel 2.6.27 – epoll limits
Yesterday we faced a strange problem. A newly set up Hadoop cluster got unstable after a few minutes. Logs reported a lot of exceptions like: java.io.IOException: Too many open files at sun.nio.ch.EPollArrayWrapper.epollCreate(Native Method) at sun.nio.ch.EPollArrayWrapper.(EPollArrayWrapper.java:68) at sun.nio.ch.EPollSelectorImpl.(EPollSelectorImpl.java:52) at sun.nio.ch.EPollSelectorProvider.openSelector(EPollSelectorProvider.java:18) at sun.nio.ch.Util.getTemporarySelector(Util.java:123) at sun.nio.ch.SocketAdaptor.connect(SocketAdaptor.java:92) at org.apache.hadoop.hdfs.server.datanode.DataXceiver.writeBlock(DataXceiver.java:281) at org.apache.hadoop.hdfs.server.datanode.DataXceiver.run(DataXceiver.java:102) at java.lang.Thread.run(Thread.java:619) or DataXceiver java.io.EOFException at java.io.DataInputStream.readShort(DataInputStream.java:298) at [...]
Typing Special Keys under Linux
Some special characters like ~ (tilde) cannot be typed by simply pressing the key combination. This is true at least for german keyboard layouts and Ubuntu 6.10 (Edgy Eft) and 7.04 (Feisty Fawn). To prevent this behaviour and display the character upon the first stroke add the following to you /etc/X11/xorg.conf under the section Input [...]
How to change encoding of a file?
Another chapter of the book “Encoding is hell” Today I noticed that some files in one of our projects suddenly have been converted to UTF-8 where they should have been in ISO-8859-1. Ok, short question: How to convert it back? Short Answer Use iconv like this: iconv –from-code=UTF-8 –to-code=ISO-8859-1 inputfile.txt > outputfile.txt