USE OF THE INFORMATION ON THIS PAGE IS AT YOUR OWN RISK !

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Notes on running CMSSW on ubuntu hardy heron

• on ubuntu, by default, when running scramv1, one sees errors like

      [: 71: ==: unexpected operator
     

  This is due to the fact that /bin/sh is linked to /bin/dash instead of /bin/bash (see also this link). One can set this back to bash by running sudo dpkg-reconfigure dash and selecting the appropriate answer.
• scramv1 complained about missing Template.pm. Doing sudo apt-get install libtemplate-perl seems to make this warning go away.
• At least with CMSSW_1_6_12, scramv1 b did not build anything even though it should have. Running scramv1 --debug b showed that it wanted to run gmake which does not exist on ubuntu. A softlink ~/bin/gmake -> /usr/bin/make (where ~/bin is in the path) made the building work.
• To get from cmstools import * or import readline to work: After creating the project area (assuming python2.4 is configured for the CMSSW version), softlink it from the local python installation, e.g. by doing:

      ln -s /usr/lib/python2.4/lib-dynload/readline.so $CMSSW_BASE/lib/$SCRAM_ARCH/
    

Running OpenAFS on ubuntu

• To start openafs, do sudo /etc/init.d/openafs-client start. If the OpenAFS kernel module does not exist (for the kernel version in use), this will complan.

• To build the OpenAFS kernel module, follow the instructions in /usr/share/doc/openafs-client/README.modules which are essentially the following ones:

         sudo apt-get install module-assistant
         sudo module-assistant prepare openafs-modules
         sudo module-assistant auto-build openafs-modules
        

  You should get a message like: Done with /usr/src/openafs-modules-....deb. Install this deb file using sudo dpkg -i /usr/src/openafs-modules-....deb.

Note that this needs to be redone when you install a new kernel version.

Running kerberized CVS

• make sure the package krb5-user is installed (for kinit)
• Make sure /etc/krb.conf exists and contains the appropriate lines for CERN. If it doesn't exist, it's probably easiest to copy it from lxplus/lx32slc4.
• Copy /etc/krb5.conf and /etc/krb.realms from lxplus/lx32slc4 after making a backup of your existing /etc/krb5.conf and /etc/krb.realms. (yes, it looks like we need krb5 files despite only getting a ticket for krb4...)

• Copy /usr/bin/cvs from lxplus/lx32slc4 and make sure you put it in a directory where it is found before the standard cvs (e.g. into ~/bin and make sure that ~/bin comes before /usr/bin/ in your PATH).

• Get a token using kinit -4 xyz@CERN.CH .
• work with CVS

ssh to lxplus using kerberos token forwarding

• Obtain a kerberos token:

   kinit xyz@CERN.CH

• At least on hardy heron, the ssh client is affected by a bug with round robin DNS hosts such as lxplus.
  • In order to have token forwarding, one must use the option GSSAPIDelegateCredentials yes (either on the command line or put it in ~/.ssh/config)
  • If you login to an explicit lxplus node (e.g. lxplus123), you won't be affected by the DNS round robin bug. Otherwise, use the option GSSAPITrustDNS yes. See also this link and this link.

CRAB

• make sure you have a file /etc/redhat-release. If not, copy it from lxplus.
• setup the environment (for bash/zsh):

    source /afs/cern.ch/cms/LCG/LCG-2/UI/cms_ui_env.sh
    eval `scramv1 runtime -sh`
    source /afs/cern.ch/cms/ccs/wm/scripts/Crab/crab.sh

(see also here).

• in order to get voms-proxy-init to work, one needs libexpat.so.0 (e.g. /usr/lib/libexpat.so.0 from lx32slc4= in my case). I copied this into the directory from which I submit the crab jobs and added $PWD at the end of the environment variable LD_LIBRARY_PATH.

• see also Storage element interaction in general
• see here for CERN storage element for CASTOR

Links

• CMSSW in chrooted SL4 (or SL3) system. Nice, but re-mounting the afs filesystem in the chrooted environment is somewhat ugly...
• installing CMSSW rpms on an unsupported distribution

PYTHON

readline

• copy /usr/lib/libreadline.so.4 from lx32slc4/lxplus, into a directory which is contained in $LD_LIBRARY_PATH$.

Personal remarks

The following are not related to Ubuntu in general but more to my personal configuration.

• The auto library loader under root (FWLite) seems not to work in my (default) setup, this seems to be due to spurious libraries in the LD_LIBRARY_PATH. I get:

  Error: Symbol G__exception is not defined in current scope  (tmpfile):1:
       

  Executing the following seems to fix it:

         export LD_LIBRARY_PATH=$(echo $LD_LIBRARY_PATH | tr ':' '\n' | grep -E "/afs/cern.ch/cms/sw|$CMSSW_BASE" | tr '\n' ':' )
       

Misc.

• For my machine, copy binaries from lx32slc4, not from lxplus

Mounting windows network filesystems

Assume you want to mount your Windows (NICE) network home directory on your Linux machine. In the following example, the mount point is /tmp/mnt (which you must create if it does not exist). Assuming your Nice login name is johndoe, try mounting your home directory as:

    sudo mount -t smbfs -o username='CERN\johndoe' -o uid=$(id -u) -o gid=$(id -g) '//cernhomej/johndoe' /tmp/mnt

(note that the servername is cernhome + the first letter of Nice login name).

Links

• CMSSW on Ubuntu in the CMS SWGuide

-- AndreHolzner - 10 Jul 2008

USE OF THE INFORMATION ON THIS PAGE IS AT YOUR OWN RISK !