= Requirements =
Before installing QCG-Computing make sure that  software listed in the next subsections is installed. You may also read distribution specific notes available for:
 * [[OpenSuse]]

== Dependend libraries ==
1. libxml2  >= 2.6.27
2. openssl >= 0.9.7
3. unixODBC >= 2.2.0
4. Python (with the lxml package) >= 2.4 

'''Note:''' If you are installing the libraries from binary packages check if those libraries were installed in '''devel''' versions (i.e. with headers files).

= Installation =
== QCG-Core library ==
[http://www.qoscosgrid.org/trac/qcg-core/downloads/  QCG-Core] is an utility and interoperability layer for the the basics QCG services (QCG-Computing and QCG-Notification in particular). As the GSI (Grid Security Infrastructure) is used to secure the transport layer you must compile the QCG-Core library with GSI support. After successful [[installingGridFTP|gridFTP installation]] (we recommend to use version 4.x or 5.x of Globus Toolkit) all you need to do is to check if the `GLOBUS_LOCATION` environment variable is set correctly (and the `$GLOBUS_LOCATION/etc/globus-user-env.sh` file sourced). You must also choose globus flavor that you wish to compile with (e.g. `gcc64dbg` for a 64bit machine or `gcc32dbg` if you are installing the QCG-Core on a 32bit machine):

{{{
#!div style="font-size: 90%"
{{{#!sh
. $GLOBUS_LOCATION/etc/globus-user-env.sh 
tar xzf qcg-core-*.tar.gz 
cd qcg-core-*
./configure  --with-globus-flavor=gcc64dbg
make
sudo make install
}}}
}}}

'''Note:''' You may need to pass some additional options to `./configure` script, if some of the dependencies are installed in non-standard locations (type `./configure --help` for more info)

== QCG-Computing service ==

After downloading the [http://www.qoscosgrid.org/trac/qcg-computing/downloads  source package] the QCG-Computing installation can be done in a few steps, e.g:

{{{
#!div style="font-size: 90%"
{{{#!sh
tar xzf qcg-comp-*.tar.gz 
cd qcg-comp-*
./configure  --with-qcg-core=/opt/qcg/
make
sudo make install
  }}}
}}}

= Configuration =
Before you start create a new system user (e.g. `qcg-comp`) that will be used by the service (and only the QCG-Computing service) to run in unprivileged mode:

{{{
#!div style="font-size: 90%"
{{{#!sh
useradd -d  /opt/qcg/var/log/qcg-comp/ -M  qcg-comp
  }}}
}}}
== Installation path ==
Please note that the source packages install QCG into `/opt/qcg` by default while the other documentation pages assumes that all commands are in standard system paths.