Using the CernVM Virtual Machine
Introduction
This page aims brings together links that explain how to run the LHCb software inside the
CernVM
virtual machine and to document any known problems. It is not about installing the CernVM-FS filesystem as a shared software area. For that, please look at the excellent
CernVM-FS deployment page
maintained by the UK
GridPP
.
Installation
The
CernVM portal
contains detailed installation instructions for a variety of virtualisation products. You may also find these page useful:
Please note
CERNVM3 requires a second host only adaptor to work with Virtualbox. If you have trouble with your virtual machine, try following the instructions found
here
if you have not already.
LHCb Software environment
When using the graphical
CernVM environment, the LHCb software setup does not always seem to run for new shells. To work around this add
if [ -f /cvmfs/lhcb.cern.ch/group_login.sh ]; then
. /cvmfs/lhcb.cern.ch/group_login.sh
fi
To your
~/.bash_profile
file.
In addition, there is a script you can source that sets up various extra settings, which you should add to your
~/.bashrc
file.
if [ -f /cvmfs/lhcb.cern.ch/lib/group_extra_settings.sh ]; then
. /cvmfs/lhcb.cern.ch/lib/group_extra_settings.sh
fi
If for some reason you prefer (t)csh, add
if ( { ( [ -f /cvmfs/lhcb.cern.ch/group_login.csh ] ) } ) then
. /cvmfs/lhcb.cern.ch/lib/group_login.csh
endif
if ( { ( [ -f /cvmfs/lhcb.cern.ch/group_extra_settings.csh ] ) } ) then
. /cvmfs/lhcb.cern.ch/lib/group_extra_settings.csh
endif
to your
~/.cshrc
or
~/.tcshrc
file.
Grid Usage
In order to use grid tools like
LHCbDirac or Ganga on
CernVM, you need to enable the Grid UI options in the
CernVM settings. In the web interface navigate to the
CernVM -> Preferences
section and in the
CernVM Groups and Repositories
section make sure
grid
is in your list of selected repositories.
You will of course need to copy your grid certificate to your
CernVM instance, under
~/.globus
, as per any other linux site. More instructions on this are available
here.
In your home directory, you should create a file
~/.dirac.cfg
in your home directory on the virtual machine with the following content
LocalSite
{
Site = DIRAC.Local.uk
}
You may change the country if you like. It will affect the location where a file is retrieved from if available in more than one place.
Troubleshooting
- If you have problems with your grid certificate not authenticating and you have followed all the usual steps try starting
ganga
and try:
gridProxy.destroy()
gridProxy.create()
- If you have problems downloading files from the grid, but otherwise the internet and your grid proxy work inside the VM, you might need to change the type of networking used by your virtualizing software. For example, in VirtualBox the default NAT mode did not work, and when using dirac-dms-get-file caused an error including the message
GSS Major Status: Unexpected Gatekeeper or Service Name
. Switching to the "NAT Network" mode worked. You can create a "NAT network" inside the VirtualBox network preferences menu, and in the network adapter settings for the CernVM itself set it as the network adapter.
Tutorials
CERNVM 2.X
CERNVM 3
Other useful Links