To start with, you need to be working on a LCG UI (user interface). Instructions for setting up a UI for yourself are available at the following CERN twiki site . The following indicators could help you in the installation. Experience written up here is with scientific linux 4.5.

• First install scientific linux 4.
• Remember to set up any proxies needed (put them in /etc/profile for example)
• Follow the instructions on the CERN twiki site and download all the needed repo files
• Do a "yum update" to update the packages. Also, install the certificates and the glite-UI as mentioned in the above guide.
• If there is any error, you will have to figure it out. For example, the python version changed between scientific linux versions 4.4 and 4.5. I needed to remove the new rpm (python 2.3.4-14.4) which is automatically installed by sl4.5 and install the old rpm (version python 2.3.4-14.3) to get the glite-UI to install.
• For getting the grid certificates to work, you will probably need to set up the variable GLOBUS_LOCATION (e.g. /opt/globus) and add the correct directory to the following variables LIBPATH (/opt/globus/lib), PATH (e.g. /opt/globus/bin), LD_LIBRARY_PATH (e.g. /opt/globus/lib). grid-proxy-init should work now.

Now you should be ready to install the LHCb software. For this, you need to set the environment variables MYSITEROOT (where you actually install the packages) and CMTCONFIG (the type of operating system it is : For example, rh73_gcc323, slc3_ia32_gcc323, win32_vc71). Then, follow the instructions given on the following web page to actually install the software.

If you are planning to install / support all the LHCb software, the following may be useful :

• Copy the script lhcbsetup.(c)sh and edit the MYSITEROOT and CMTCONFIG (and whatever else you need). You can source this file to get the environment variables setup.
• This script should come with any LHCb package installation.
• If it has not come with your installation for some mysterious reason, get it from /afs/cern.ch/lhcb/scripts/lhcbsetup.(c)sh
• Remember you need also to source $MYSITEROOT/scripts/ExtCMT.(c)sh. This will set up most of the aliases for the LHCb package environments.
• In case of Ganga, you will need to look at the directory structure to set up the GangaEnv. This is / will be explained in more detailed on the Ganga web pages
• I have had complaints from cmt.exe about the following missing directories. Creating the necessary directories and symbolic links to (at RAL) $LHCBHOME/lhcb solved the problem. This seems to arise from the difference in the directory structure of LHCb software at CERN and the structure as installed using the installation package.
• $LHCBHOME/software/releases
• $LHCBHOME/software/NEW
• $LHCBHOME/software/DEV
• Also remember to use the correct (i.e. latest supported) version of cmt. There is no easy way except to ask around. The LHCb software librarian (currently Hubert Degaudenzi : Hubert dot Degaudenzi at cern.ch) should probably be your starting point.
• The "getpack" command (again in the same scripts directory as the first bullet) does not seem to work with kerberos authentication. It however works with ssh authentication. The way to set it up is as follows :
• Set the following environment variables :

GETPACK_USER < CERN lxplus username >
CVS_RSH = ssh

• Use the command : getpack -f ssh < package > < version >
• For those who want to get rid of the repeated annoying prompts for the password, the website at CERN on cvs access should help.

The core list of software you will probably need to install - with everything else following automatically - is given below. The generic instructions for installing these are in the pages mentioned above.

BENDER    (Python based analysis)
BOOLE     (Digitisation)
BRUNEL    (Reconstruction)
DAVINCI   (Analysis)
GAUSS     (Simulation)
HLT       (High Level Trigger)
Orwell    (Online monitoring)
PANORAMIX (Event display)

If you donot have an AFS client, the instructions for DIRAC are given here in their savannah page. If you want to install a specific version of DIRAC, look at the options of the install script (./dirac-install --help) after downloading it according to the instructions. You will probably need a command along the following lines :

../dirac-install -g -p http://lhcb-wdqa.web.cern.ch/lhcb-wdqa/distribution/DIRAC_v2r17.tar.gz

For more information : contact Raja Nandakumar ( R dot Nandakumar at rl dot ac dot uk )