Q. I was reading this article and wanted to try out KVM, XEN, VMWare and VirtualBox simultaneously on my desktop system with 2GB RAM? Why I’m not able to use run multiple virtualization technologies simultaneously under Ubuntu Linux? Can a Linux server run multiple virtualization technologies simultaneously?
I’m not able to boot into GUI under Dell desktop system, which uses an ATI HD3750 display card. The display only works with CLI and but when I type startx and get some sort of error or a black screen. How do I fix this issue?
Q. I’m trying to login to my remote Ubuntu Linux server from Mac OS X desktop using following command:
ssh -X email@example.com xeyes
But I’m getting an error that read as follows:
X11 connection rejected because of wrong authentication.
How do I fix this error?
Q. I’d like to keep same login screen for my school Linux desktop system lab. How do I create a custom gnome login screen or menu under CentOS or Ubuntu Linux desktop systems?
Q. How do I change default desktop / display manager under CentOS or Fedora Linux? I’d like to change default GNOME to KDE as desktop manager for all users.
A. There is a configuration file called /etc/sysconfig/desktop. This file defines default display manager and desktop name.
Display manager can be any one of the following:
[a] gnome (gdm)
[b] kde (kdm)
[c] xdm (xdm)
Desktop can be any one of the following
Change Desktop from Gnome to Kde
Open /etc/sysconfig/desktop file:
# vi /etc/sysconfig/desktop
Set DESKTOP variable to kde:
Save and close the file.
Now kde will be used for all users as desktop system. You can also accomplish this on a per-user basis by using the desktop switcher application from the extra preferences menu, or just type the command:
$ switchdesk kde
=> Quick way to switch from KDE to GNOME or viceversa
Q. Iâ€™m using Ubuntu Linux and Iâ€™d like to create or modify keyboard shortcuts in Gnome desktop system? How do I do it?
A. You need to use GConf-Editor or gnome keyboard shortcut tool. GConf-Editor is a tool used for editing the GConf configuration database. It might be useful when the proper configuration utility for some software provides no way of changing some option. The main window consists of a tree showing the GConf configuration database hierarchy, a list of the keys available, and documentation for the selected key. Key values can be changed by either changing them directly in the list, or right clicking on them and selecting Edit key. Changes take immediate effect in running programs. New keys can be added by right clicking in the list and selecting New key.
Easy to use – Keyboard Shortcuts tool
Use the Keyboard Shortcuts preference tool to customize the default keyboard shortcuts to your requirements.
Click on System > Preferences > Keyboard Shortcuts to launch the application and view the preconfigured shortcuts.
To edit a keyboard shortcut, perform the following steps:
- Click the action in the list. If you are using the the keyboard, use the arrow keys to select the shortcut and press Return.
- Press the new key or key combination you want to assign to the action.
- To clear a shortcut, press Backspace. The action is now marked as Disabled.
- To cancel assigning a shortcut, click elsewhere in the window or press Escape.
Advance keyboard shortcuts tool – gconf-editor (GConf-Editor)
You need to install this tool using any one of the following command (Debian / Ubuntu Linux):
$ sudo apt-get install gconf-editor
Or if you are using Fedora / CentOS /RHEL Linux:
# yum install gconf-editor
Use menus or type a command as follows:
$ gconf-editor &
- Next double click the “apps” folder
- Next double click the “metacity” folder
- Finally click the global_keybindings folder
Please note that all these keyboard shortcuts and other settings are saved on a user basis (inside a home directory), so each user can create their own custom setup.