In this post, I discussed "clone" mode of dual head with xrandr 1.2. Now I got an extra monitor, and would like to use "xinerama" mode, wherein the built-in laptop LCD and the external monitor share a single virtual screen. To set this up, I changed my /etc/X11/xorg.conf to add a monitor section for the external monitor:
Identifier "Intel 965GM"
Option "XAANoOffscreenPixmaps" "true"
My work requires me to connect to many different SSH servers, and I have different passwords for each server. It's a pain in the neck trying to type in many different passwords everyday. The obvious solution is to use OpenSSH's public key login solution, so passwords are no longer needed to connect to SSH servers from a single client (e.g. my office desktop).
Key Generation and Distribution
To use public key authentication, it is necessary to generate a pair of keys on your client machine. Do the following as normal user:
Most of Linux laptop users have done some customizations on the system so it works the way we wanted. Now we want to save the fruit of our hard labor in case bad things happen. We want to backup not just the /home directory, but the whole / directory, minus some runtime generated files. In the past I have used some heavy-weight applications such as unison and backuppc. These worked well, but they required setting up servers that run all the time.
Command line manual page is an indispensable tool for working with Linux system.If you forget how to use a command, just type man followed by the name of the command. One thing I don't like about the manual system on my Debian sid is that it uses most to display the manual. The key bindings of most feel awkward for me since I am used to vim. Of course, there are many "vimers" like me, and they've found ways to fix this.
These day I write Java programs on my local machine and then move them to a Linux server to run experiments. This routine works fine so far. However, when I ran one of the progams, which involves coping one file from one directory to another, I kept on the following error message:
All of my laptops are now running Debian based Linux. It works great. Linux handles all my daily works well. However, there are occasions where I need a Windows machine. For example, I recently need to deliver a lecture on a system that runs only on Windows. Also, in the past, we developed a system that works only on Windows, and I still need to demonstrate it from time to time. Of course, the solution is to run Windows on a virtual machine on top of Linux. In the last couple of years, I have been using VMware for this purpose. However, I was not very impressed by its performance. I remember last year during a presentation, the virtual machine was so slow that my demonstration was negatively impacted by it.
Open source edition
On my old Thinkpad X31, there is a nice little program called tpb that makes all Thinkpad hotkeys work on Linux. However, that project hasn't been updated for two years, and tpb does not work with the newer Thinkpad models. On my new X61, notably, the sound volume controls are broken: volume UP and volume Down keys produce the same effect - bring the volume to the half level. It seems that piece of hardware called nvram, on which tpb relies, now produces different values than older models. So, I have to ditch tpb.
Thinkpad X61 has an VGA output port, so it supports dual-head display. However, with the Intel GMA965 graphics chipset in X61, the thinkpad_acpi (used to be called ibm_acpi) kernel module does not seem to support switching on or off this VGA port any more. The traditionally used commands, such as "echo crt_enable > /proc/acpi/ibm/video", no longer work.
Fortunately, the xserver-xorg-video-intel display driver supports xrandr 1.2. extension in recent versions of Xorg X server. So we can use xrandr to dynamically switch on or off the external VGA display, and much more.