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Creating a CentOS C7 Virtual Machine

(Prepared by A. Poyet)

Step 1 : Create a new OpenStack instance

The first step is to create an instance using the OpenStack service at CERN. From this website, click on 'Instances'.

Set the details of your machine

Simply choose a name that will be convenient for you.

Choose a source

We recommend to choose as source an image of the CC7 OS.

Choose a flavour

Here you can choose the number os CPUs, and memory you need, choosing between three possible sizes (small, medium large). For a fast creation, we recommend to request a small one.

Create a key pair

In order to access your machine by ssh, you need to create (actually import) a key pair. For that, go to your terminal and issue the following command:

ssh-keygen -t rsa -f apoyet-lxplus.key

NB: apoyet-lxplus.key corresponds here to the name of the key I'm creating

Now import the key pair in your instance by clicking on 'IMPORT KEY PAIR' and copy pasting the public key you just created

And launch your instance (~20 min).

Step 2: Access your machine

Once the instance is running, you should be able to access it via ssh as root:

ssh -i apoyet-lxplus.key root@apoyet-lxplus

It seems that a user corresponding to your NICE account is already created.

ssh apoyet-lxplus

And AFS is already mounted.

Step 3: Mount CVMFS

Access your machine as root. And issue:

locmap --enable cvmfs
locmap --configure cvmfs

Step 4: Mount EOS

Access your machine as root. And issue:

locmap --enable eosclient
locmap --configure eosclient
Once connected as user on your machine, you will need to create a token to access EOS. This is done by issuing two commands:


You can install git with

sudo yum install git

You can install jvm with

sudo yum install java-1.8.0-openjdk
This will be useful for pytimber and other codes.

You can also install the standard development tools, for example,

sudo yum install centos-release-scl
sudo yum install devtoolset-8
to help standard compilations.