Difference between revisions of "LHCb Software At Nikhef: Prepare for Workshop 22-24 June 2009"
Line 120: | Line 120: | ||
</pre> | </pre> | ||
− | |||
− | |||
− | |||
− | |||
− | |||
− | |||
− | |||
− | |||
− | |||
− | |||
− | |||
− | |||
− | |||
− | |||
− | |||
− | |||
− | |||
− | |||
− | |||
− | |||
− | |||
− | |||
− | |||
− | |||
− | |||
− | |||
− | |||
− | |||
− | |||
− | |||
− | |||
− | |||
− | |||
− | |||
− | |||
− | |||
− | |||
− | |||
− | |||
− | |||
− | |||
− | |||
− | |||
− | |||
− | |||
− | |||
− | |||
− | |||
− | |||
− | |||
− | |||
− | |||
− | |||
− | |||
− | |||
− | |||
− | |||
− | |||
− | |||
− | |||
− | |||
− | |||
− | |||
− | |||
− | |||
− | |||
− | |||
− | |||
− | |||
− | |||
− | |||
− | |||
− | |||
− | |||
− | |||
− | |||
− | |||
− | |||
− | |||
− | |||
− | |||
− | |||
− | |||
− | |||
− | |||
− | |||
− | |||
− | |||
− | |||
− | |||
− | |||
− | |||
− | |||
− | |||
− | |||
− | |||
− | |||
− | |||
− | |||
− | |||
− | |||
− | |||
− | |||
− | |||
− | |||
− | |||
− | |||
− | |||
− | |||
− | |||
− | |||
− | |||
− | |||
− | |||
− | |||
− | |||
− | |||
− | |||
− | |||
− | |||
== Configuration of CernVM == | == Configuration of CernVM == |
Revision as of 09:45, 18 June 2009
Introduction
The B-Fys workshop will not take place at a high energy physics lab. For these reasons, it is recommended that people install a virtual machine on their laptops in order to be able to run LHCb software locally, without necessity of an internet connection. Whereas this is not a "standard" way of performing analysis at the moment, it might be beneficial to set this up anyway. In what follows, there are explanations on how to run either with an internet connection to nikhef, or with a local virtual machine. Once the installation has been done and the environment set correctly, running on the virtual machine should be the same as running at Nikhef.
Running at Nikhef
Logon at Nikhef
ssh user@ribble.nikhef.nl ssh stbc-16 (on stoomboot)
Set the environment
Here we set the environment for DaVinci, but it could also another LHCb application, like Bender or Panoramix.
mkdir cmtuser cd cmtuser source /project/bfys/lhcb/sw/setup.sh # for sh, bash, ksh, zsh source /project/bfys/lhcb/sw/setup.csh # for csh, tcsh SetupProject --build-env DaVinci v23r1 # makes a DaVinci_v23r1 directory if one doesn't already exist SetupProject DaVinci v23r1 # exports environment variables to the shell
(NB: zsh-users should add 'setopt SH_WORD_SPLIT' to their .zshrc )
Running on a virtual machine on your very own laptop
This assumes you have successfully installed a CernVM on your computer. The installation varies between Windows, Mac OS and Linux, so see section further down for instructions on how to set it up. It also assumes you have set up basic login scripts, and installed AFS, X11R6, CVS and SVN if necessary. Also note that you have to run an application like DaVinci, Bender or Panoramix at least once while connected to the network in order to cache the necessary software.
Log onto your CernVM
This could mean starting the virtual machine and CernVM, starting it and logging in "remotely" from a terminal (Linux, Mac) or Exceed (Windows). Linux/Mac login
ssh -Y -p 2222 CernVMUserName@localhost
Windows login
Start exceed Start ssh Connect to vm with ssh to 192.168.204.128 (Your number might be different!) (fink tunnel x11 connections in ssh!)
AFS access
If you need access to CERN AFS areas,
klog user@CERN.CH
Where user is your CERN AFS username. Note the UPPER CASE for the domain name. Be careful: Never do: ls /opt/ !! (It could start caching all atlas software...).
Set the environment
This is the same as in the remote login to Nikhef, except that the LHCb environment should be set when you log in if you have set up your CernVM correctly.
SetupProject --build-env DaVinci v23r1 # makes a DaVinci_v23r1 directory if one doesn't already exist SetupProject DaVinci v23r1 # exports environment variables to the shell
The main difference here is that if you do not have the necessary software installed, CernVM will pull it and cache it for you. So the first time you do this you should have an interned connection.
Running over some events on a DST or MicroDST
After the environment has been set (either by remote login to Nikhef or CERN, or in the local CernVM on your laptop, we can start some simple analysis:
Get a nice package full of example scripts (new Bender Examples package exists too...)
If you haven't already got an examples package, get it, as you might need to perform modifications to some of the scripts. This has to be done when you have access to the internet.
getpack -p anonymous Ex/MicroDSTExample v2r5
cd ~/cmtuser/DaVinci_v23r1/Ex/MicroDSTExample/scripts python -i MicroDSTReadingExample.py --input /data/bfys/h71/Workshop/SeqDC06selBs2JpsiPhiWithMC_50.0_Kevt_NoPVReFit.dst
Plot some of the histograms made by the script
>>> massPlots[443].plot() >>> massPlots[531].plot() >>> massResPlots[531].plot() >>> propTimePlots[531].plot() >>> Ctrl-D
Some more examples, using Gaudi or Bender environments and example scripts. Note we run them directly without getpacking them.
SetupProject Gaudi v21r0 python $GAUDIEXAMPLESROOT/python/HistoEx.py SetupProject Bender v12r0 cd $BENDEREXAMPLEROOT/python/BenderExample/ ./Phi.py
Introduction to Python
It is important that attendees make themselves familiar with the python programming language, at least at the level of writing simple scripts.
Extensive tutorial: Tutorial
Cheat Sheet: Cheat Sheet
/user/h71> python >>> hello = "Hello world" >>> print hello >>> Ctrl-D
Configuration of CernVM
This configuration of CernVM is platform independent. A few things need to be set up before we can start playing
Login scripts
If you want the LHCb environment to be correctly set by default each time you login, the following is necessary:
/opt/lhcb/group_login.sh (csh) has to be sourced at the end of the .bash_profile (.login)for bash (tcsh).
/opt/lhcb/group_shell.sh (.csh) SHOULD be sourced at the end of the .bashrc (.tcshrc). However, this doesn't work at the moment and Hubert claims it doesn't really make a difference for now.
The most important one for us, /opt/lhcb/LbLogin.sh (csh), should be sourced, I do this in my .bashrc (.tcshrc).
Installing missing software
I found that I was missing SVN, CVS and, less importantly for the workshop, AFS. To install these, it is necessary to get the packages:
sudo conary update cvs sudo conary update subversion sudo conary update openafs=1.4.8-1-1 sudo conary update openafs-client=1.4.8-1-1 sudo conary update openafs-kernel=1.4.8-1-1
AFS has to be started:
sudo /etc/init.d/afs start
I also found that there was no gmake command. In CERN Linux this is just a symbolic link to /usr/bin/make but cmt calls gmake, so we need to have it. I just hacked it by making a link:
sudo ln -s /usr/bin/make /usr/bin/gmake
If you are using C-shell, remember to do type
rehash
to update the paths, otherwise you won't see cvs, klog, etc. until the next time you log it.