Yum don’t work in clean CentOS 7 – How to fix it?

Today, I have been banging my head on the wall to find the solution for the following mysterious problem. Whenever I run any command in the Terminal, be it a installing a package or updating the system, my CentOS 7 minimal system threw the following error.

Loaded plugins: fastestmirror
Loading mirror speeds from cached hostfile
 * base: centos.excellmedia.net
 * elrepo: ftp.nluug.nl
 * extras: mirrors.vonline.vn
 * updates: mirrors.vonline.vn
Traceback (most recent call last): 27% [================ ] 140 kB/s | 2.5 MB 00:00:48 ETA 
 File "/usr/libexec/urlgrabber-ext-down", line 75, in 
 File "/usr/libexec/urlgrabber-ext-down", line 61, in main
 fo = PyCurlFileObject(opts.url, opts.filename, opts)
 File "/usr/lib/python2.7/site-packages/urlgrabber/grabber.py", line 1258, in __init__
 File "/usr/lib/python2.7/site-packages/urlgrabber/grabber.py", line 1589, in _do_open
 File "/usr/lib/python2.7/site-packages/urlgrabber/grabber.py", line 1723, in _do_grab
 File "/usr/lib/python2.7/site-packages/urlgrabber/grabber.py", line 1517, in _do_perform
 raise KeyboardInterrupt

Exiting on user cancel

I neither cancel the process nor interrupt the keyboard, but my CentOS 7 virtual machine was continuously giving the above error. I tried so many times, but I couldn’t install any packages or update the system.

Thankfully, I found a solution from this thread.

Here it is what I did to solve the problem.

From your Terminal, run the following commands one by one as root user:

yum clean metadata
yum clean all
yum upgrade

Or, simply run the one line command as root user:

bash -c 'yum clean metadata && yum upgrade'

That’s it. Problem is gone! Now, I could install any software without any issues.

Good day!


Here is the default set of wallpapers in Ubuntu 15.10 Wily Werewolf

As you all may know, Ubuntu 15.10 final beta has been released a week ago and Ubuntu 15.10 final stable version will be released officially on Thursday October 22, 2015.

In case you want to upgrade your old Ubuntu version to Ubuntu 15.10 final beta, check this link.

Two days ago, Ubuntu development team has revealed the default set of wallpapers in Ubuntu 15.10. Based on the community voting, here is the 10 stunning wallpapers which are going to be included in Ubuntu 15.10, codenamed Willy Werewolf, final release.











You can download all above images from this link.

To see all images of Ubuntu 15.10 wallpaper contest, check the following link.

To download Ubuntu 15.10 complete Wallpaper contest images, click the following link.

Ubuntu 15.10 Default background wallpaper

Here is the default background wallpaper of Willy Werewolf.


Download the full HD default background from the link below:

That’s it. Hope you will like the new set of default wallpapers in Ubuntu 15.10.



OSBoxes – Free Unix/Linux Virtual machines for VMWare and VirtualBox

I have been using Linux for the past five years. My first operating system was CentOS. Later, I moved to OpenSUSE, and tried many distros such as Debian, Fedora, finally now I am using Ubuntu as my primary operating system. In the past, I am not aware of Oracle VirtulaBox or VMWare. So I formatted my Laptop and Desktop four to five times per month and played with different Linux operating systems. This is really time-consuming and I didn’t know how to test an operating system without formatting the Host OS.

One day, one of my colleague advised me to use any Virtualization tools such as VirtualBox and VMWare etc. He told me that these tools will help you to install and test most operating systems of your choice without formatting the Host OS. I felt happy and immediately installed VirtualBox on my Laptop and started to test various Linux distributions. Now, I installed Ubuntu 14.04 LTS as my Host OS and installed Oracle VirtualBox in it, so that I can install and play with any OS of my choice in my Laptop. These tools are really helpful if you wish to test different operating systems.

Now, I have more than 20 guest operating systems in my Laptop and Desktop. Also, I am maintaining a backup copy of all VMs. So, whenever I want to test a new tool or software, I simply copy/paste the fresh VMs form the backup and started to test those tools or OS. This method helped me lot of times. I really don’t have to format my Laptop/Desktop every time to test a new tool or OS. If you’re anything like me, I have good news for you. Meet OSBoxes, an ideal place to find and download all popular Unix/Linux Virtual machines. You are free to download and use any VM of your choice.

OSBoxes is founded and maintained by Umair Riaz, a Computer science student and Geek. He is specialized in networks, and also he is running an another website called NoobsLab. As the name implies, NoobsLab publishes open source and Linux related stuffs everyday, especially for beginners. The idea behind OSBoxes is to provide virtual machines so anyone can download and use it regardless of host OS. There are some reasons that some people (who use other OS) may want to try Linux before they migrate to it, some people simply don’t want to dual boot their system or they have some kind of hardware issue, and some people use Linux but also work on other distributions at the same time. That’s why OSBoxes was born.

OSBoxes offers ready-to-use Unix/Linux guest operating systems for both architectures 32bit and 64bit for free. At the moment, OSBoxes offers 30+ Linux/Unix distributions, but they may add more to the list in near future. Want to try some VMs? Then, download them from the following links.

All images for VirtualBox and VMware have the same username and password. After logging into virtual machine that you’ve downloaded from here you can change ‘username’ & ‘password’ or create you new user.

  • Username – osboxes
  • Password – osboxes.org

For Root user account:

  • Password – osboxes.org

Also, you can find the login details in the download page of respective VM.


Cool, isn’t? Just download the VM of your liking and play with it.

If you don’t know, how to use these VM images in VirtualBox and VMWare, check the following guide.

For more details, check the official FAQ section.

That’s all for now. Hope you find it useful.



LabxNow – A Free Online Cloud Lab for Linux Enthusiasts

LabxNow – OS in the Web browser

Today, we have a very very interesting news for Linux enthusiasts. Now, you can play with your favourite Virtual machines right from your Web browser itself for absolutely free of cost. You don’t need to buy an expensive VPS or deploy any virtualization platforms on your local server to setup Virtual machines. LabxNow, a free online Research and Development environment, offers pre-configured VMs for free. You are allowed to install any software or tool of your choice on the VMs and do whatever you want without paying a penny. Sounds great, isn’t it?

You can access the VMs from anywhere from any Internet enabled devices such as Laptop, Desktop, Mobiles, and Tablets etc. All you need is a decent Internet connected device. Forget about high cost VPS, domain space or hardware support. Just sit in your Home, backyard, Office, Park or anywhere and start use your VM.

LabxNow is founded by Ken Zheng. He says,

“Being in the I.T. industry for over 20 years, I spent lots of time either fighting with the I.T. support team for hardware, or my wife for the money I needed to pay for it.”

He also quoted in his website,

“Given the utilization rate of servers is ~15% around the world, there should be lots of unused resources out there. With a 5-year-old server I got early last year, and the experience with cloud, we started utilizing Docker, KVM, Guacamole, and more, to put together what we have right now.

Surprisingly, we launched 1350 ContainerVMs on the 5-year-old server with extremely smooth access to the remote desktop over the browser. We think we might have found a way to share the hardware in a cheap way!”

How LabxNow works?

The LabxNow is an efficient blend of virtualized machines hosted in their data centers. The technologies which are used by LanxNow are given below.

  • Docker: All of our supported Linux distributions will be virtualized through the use of Docker Containers and custom Docker Images.
  • KVM: The more heavy-weight operating systems will be virtualized through KVM (Kernel-based Virtual Machine).
  • Guacamole: Remote access through the web browser made using Guacamole to a existing RDP (Remote Desktop Protocol and/or it’s Linux derivative XRDP), or VNC connection on the virtualized endpoint machine.


Concerning about the features, we can list the following:

  • OS on a browser ;
  • You are free to install any software or tools ;
  • Add, delete, manage your VMs from anywhere ;
  • Fully customizable VMs ;
  • Cluster ;
  • And more.

Getting started with LabxNow

Go to the LabxNow website: https://www.labxnow.org/labxweb/

Sign up or create your account. It is completely free. You can also signup with your existing social networks such as Facebook or Google.

Each registered user will get free virtual private servers with 2 Cores, 4G RAM, and 10G SSD.

Here it is how my LabxNow dashboard looks like.

LabxNow | Projects Portal - Google Chrome_005

Once you registered with LabxNow, two virtual machines will be automatically deployed for you; the machines are Ubuntu 14.04 and Red Hat Enterprise Linux 6.5. Please note that you can’t delete the default VMs, however you’re free to install any software or tool of your choice.

First of all create your new project. To do that, click on the plus sign (+) besides the Projects tab on the left. Then click on the Labx tab to start your free virtual environment.


Once you started the Labx environement, two machines will automatically deployed for you. You can view the pre-installed VMs under Machines in Environment tab on the left.

LabxNow | Projects Portal - Google Chrome_002

To power on the system, just click on it

LabxNow | Projects Portal - Google Chrome_009

See, my Ubuntu 14.04 XFCE system is live now. Just click on the desktop anywhere. You will get the full desktop. The side panel will be automatically hidden after click on the empty space of your Ubuntu 14.04.

LabxNow | Projects Portal - Google Chrome_010

Now, feel free to install any software of your choice or start coding your projects.

LabxNow | Projects Portal - Google Chrome_012

To power off the system, hover your Mouse cursor on the left side of your Desktop. The LabxNow panel will appear. Click on the Stop icon to turn off the VM.

LabxNow | Projects Portal - Google Chrome_011

Creating new VM

Let us create a new virtual machine. To do that click “add a new machine”.

Enter the name of your Virtual machine. Select the OS image you want to deploy from the Machine image drop down box. Then, select the CPU cores and RAM size. Finally, click “Create New Machine” to deploy the VM.

LabxNow | Projects Portal - Google Chrome_004

By default, you can create only one additional VM on top two default machines. However, you can add an additional machine for every 5 new users successfully referred.

Cluster Management

You can stop and start VMs machines either individually or as a cluster. You will have 3 machine slots in the environment; the 2 default machines cannot be deleted, and you can use the remaining slot (third slot) to add an additional machine. If you want to add additional machine, delete the newly created VM and add another VM. Also, refer 5 users, you may get extra slots.



LabxNow allows you to use all VMs as your personal work spaces. You can do whatever you want to do. LabXNow will be useful for Programmers, Linux enthusiasts, software developers, System administrators and also for all who wants to learn Linux. For now LabxNow will provide all services completely free of charge. This includes all usage and management of user environments will be free. Also, if you find it useful, you can donate or consider other forms of supporting services. For more details, contact support@labxnow.com.


All VMs hosted in the LabxNow may not be available all time. Also, It is not a safe place to put or test your important data of any kind. Use it with caution. It is just a web service that will offer free VMs for learning and testing purposes.

Good luck!


Some softwares are not working after uninstall Moksha desktop from Ubuntu 14.04 LTS

Recently, I have tested Bodhi Linux’s default desktop environment “Moksha desktop”. The Bodhi Linux developer has replaced Enlightenment desktop, which is default DE of Bodhi previous versions, with Moksha desktop due to lack of support and issues. Moksha DE is the fork Enlightenment desktop that has added features and bug fixes.

For more details about Moksha desktop, please refer the following link.

After playing with Moksha desktop for a couple of days, I uninstalled it and wanted to test a new tool. As a Linux enthusiast and technical writer, I used to test many tools everyday.

After uninstalling Moksha desktop and Bodhi desktop, I really had some issues. Yes, some softwares are not working after uninstall the Moksha desktop. Even, I can’t update VirtualBox Extension packs to the latest version. Whenever I tried to update the Extension Pack, I got the following error:

The installer failed with exit code 1: Traceback (most recent call last):
  File "/usr/bin/gksudo", line 5, in <module>
    import esudo.esudo as esudo
  File "/usr/lib/python2.7/dist-packages/esudo/esudo.py", line 13, in <module>
    from efl import ecore
ImportError: libecore.so.1: cannot open shared object file: No such file or directory

VirtualBox - Error_001

It seems the libcore package might be deleted after uninstalling Moksha desktop. I searched on the Ubuntu forums a bit and got solution.

Yes. Here it is what I did to solve this issue.

First, I installed packagekit using command:

sudo apt-get install packagekit

Then, I reinstalled the package libecore1 with command:

sudo apt-get install --reinstall libecore1

Now, remove the VirtualBox extensions using command:

sudo vboxmanage extpack uninstall "Oracle VM VirtualBox Extension Pack"

Sample output:

Successfully uninstalled "Oracle VM VirtualBox Extension Pack".

Check if all extensions have been properly removed using command:

vboxmanage list extpacks

Sample result:

Extension Packs: 0

Please note that you have to run the command “sudo vboxmanage extpack uninstall” until you got the “Extension packs” result as 0.

Once you removed all extension packs, download the latest extension pack from the Oracle VirtualBox site. Go to your download and install it using command:

sudo vboxmanage extpack install Oracle_VM_VirtualBox_Extension_Pack-5.0.4-102546.vbox-extpack

Sample output:

Successfully installed "Oracle VM VirtualBox Extension Pack"

That’s it.

Check new extension pack has been installed or not using command:

vboxmanage list extpacks

Sample output:

Extension Packs: 1
Pack no. 0: Oracle VM VirtualBox Extension Pack
Version: 5.0.4
Revision: 102546
Description: USB 2.0 and USB 3.0 Host Controller, Host Webcam, VirtualBox RDP, PXE ROM, Disk Encryption.
Usable: true 
Why unusable:

As you see in the above output, the latest version VirtualBox extensions has been added.

Hope this tip will useful for you someday.

Thanks for stopping by. Have a good day!