Pairing a CernVM with CernVM Online
Pairing an instance is the simplest way to apply contextualization information to your CernVM instance. Assuming that you have already created a context definition for your case, it only takes 2 steps. (If you haven't created a context definition yet, see the Create new context guide)
1. Pick a context definition
Log-in to CernVM online using your CERN or CernVM online account and click on the Pair an instance link on the left navigation menu.
Find the context you want to apply to your VM and click on the Pair with this context button.
You will be presented with a 6-digit pin number. Remember this pin.
2. Pairing the VM
Go to your VM, enter '#' followed by te PIN as a login name and hit enter.
Your virtual machine will be automatically contextualized and rebooted - if needed. After the contextualization process you are ready to use your machine
You can acknowledge that the VM is successfully paired from the CernVM online portal. Upon successful pairing you will be redirected to the status screen where the UUID and the IP of the machine is displayed.