Installation of a CREAM CE

From Gridkaschool

The CREAM CE can be installed via yum. All glite yum repositories are available at For the CREAM CE select release 3.2.

The required repositories are:


The repository files have to be stored in directory /etc/yum.repos.d/. The DAG repository has to be replaced:

cd /etc/yum.repos.d
rm -f dag.repo
wget -P /etc/yum.repos.d/
wget -P /etc/yum.repos.d/
wget -P /etc/yum.repos.d/
wget -P /etc/yum.repos.d/

Installing the packages

Now the software has to be installed. Aside from the CREAM Compute Element packages you need also to install the Torque client software.

yum install glite-CREAM glite-TORQUE_utils
yum install lcg-CA

If asked to accept importing the gpg keys of the repository answer with "y":

Importing GPG key 0x836AAC2B "Gd Integration <>" from
Is this ok [y/N]: y

Additionally the certificates of all VOMS server for VOs supported by your site have to be stored in the directory /etc/grid-security/vomsdir. In our case this is for dech VO.

Download the dech VOMS certifiacte from the CIC portal ( and save it under /etc/grid-security/vomsdir/ Alternatively you can get the certificate from

mkdir -p /etc/grid-security/vomsdir
wget -O /etc/grid-security/vomsdir/

Check the contents (validity, issuer, ...) of the downloaded certificate by

cd /etc/grid-security/vomsdir/
openssl x509 -in -text -noout

The output of this command is given below

       Version: 3 (0x2)
       Serial Number: 10039 (0x2737)
       Signature Algorithm: sha1WithRSAEncryption
       Issuer: C=DE, O=GermanGrid, CN=GridKa-CA
           Not Before: Nov 13 15:37:26 2009 GMT
           Not After : Dec 13 15:37:26 2010 GMT
       Subject: C=DE, O=GermanGrid, OU=Fraunhofer SCAI, CN=host/

A basic validity check for the certificate can be performed with

openssl verify -CApath /etc/grid-security/certificates/ /etc/grid-security/vomsdir/

The output should be

/etc/grid-security/vomsdir/ OK

Proceed to the CREAM CE Configuration

Go back to CREAM CE, gLite Administration Course