Daily Archives: 17 March 2017


CentOS: prevent eth0 from starting at boot time

On a CentOS server we own, we had to disable eth0 from starting at boot time
To do so we needed to modify the file /etc/sysconfig/network-scripts/ifcfg-eth0 and set the value ONBOOT="yes" to ONBOOT="no".

Using you favorite text editor, make this change and restart your machine to verify that the change was successful.

Below is the sample content of /etc/sysconfig/network-scripts/ifcfg-eth0 after the change was applied to prevent eth0 from starting at boot time.

  GNU nano 2.3.1                File: /etc/sysconfig/network-scripts/ifcfg-eth0                             Modified

TYPE="Ethernet"
 BOOTPROTO=dhcp
 DEFROUTE="yes"
 IPV4_FAILURE_FATAL="no"
 IPV6INIT="yes"
 IPV6_AUTOCONF="yes"
 IPV6_DEFROUTE="yes"
 IPV6_FAILURE_FATAL="no"
 NAME="eth0"
 UUID="792d6842-221d-5c99-ba98-cddbba4ff263"
 ONBOOT="no"
 HWADDR="00:AA:5D:01:22:2B"
 DNS1="10.15.10.5"
 DOMAIN="bytefreaks.local"
 IPADDR=10.15.10.249
 PREFIX=24
 GATEWAY=10.15.10.1
 PEERDNS=yes
 PEERROUTES=yes
 IPV6_PEERDNS=yes
 IPV6_PEERROUTES=yes
Advertisements

How to use git features on a local project without a Git server

Like many of you, sometimes we develop code that does not belong to a Git server.
Working as so, one would think that we would miss all the features of a Version Control System (VCS).
Fortunately, this assumption is wrong.
Using the already installed Git tools, we can create a new local repository in any system folder with no additional configuration.

To do so, and create a new repository from an existing project, we need to do the following using a terminal/shell:

  1. Navigate into the directory that contains the project e.g. cd /home/bytefreaks/Projects/Party/banana/
  2. Type git init
    This command will create an empty Git repository in that folder and it will produce a message as follows:
    Initialized empty Git repository in /home/bytefreaks/Projects/Party/banana/.git/
  3. In case you have files that should not be included in your repository, it is better that you create a .gitignore file and add them there.
    This way you will be able to indicate all of the files that you don’t want to the repository to track.
  4. Use git add . (please note that you need the dot . for this command)
    This command will stage all files that are not in .gitignore to be part of your next commit.
  5. Finally, type git commit or git commit -m "Initial Commit with status bla bla", to make your first commit to the repository
  6. Profit!

By now, you should have a fully functional local git repository without the assistance of an external server.


Send ALT+CTRL+Delete to QEMU virtual machine 1

Recently we wanted to start a Windows virtual machine from a physical hard disk using a Fedora w/ GNOME 3 host machine to change the domain password of a user.
To do so, we used QEMU, QEMU is a generic and open source machine emulator and virtualizer.

To perform the password change, we needed to sent the ALT+CTRL+Delete key combination to the virtual machine to access the system screen and then change the user password.
Pressing ALT+CTRL+Delete on the Fedora/GNOME 3 host machine, it popped up a prompt to shut down the host machine instead of sending the key combination to the active window of the VM. Apparently, we could not sent the key combination directly to the VM and had to find a way around it.

Solution:

We pressed ALT+CTRL+2 while the QEMU window was selected/active to switch to the QEMU terminal/monitor.
In the blank screen that appeared, we typed sendkey alt-ctrl-delete and pressed the Enter key.
This action sent to the virtual machine OS the key combination ALT+CTRL+Delete.
Finally, to switch back  to the guest screen we pressed ALT+CTRL+1.