====== Compute Element (CE) ======
===== Requirements =====
Need hostcert.pem and hostkey.pem installed in /etc/grid-security and owned by root:root. See [[grow:installation:certificates|here]] for instructions on how to do so.
===== Installation =====
The CE is installed on our grid node, grow-grid.its.uiowa.edu. [[https://twiki.grid.iu.edu/bin/view/Documentation/Release3/InstallComputeElement|Here]] are the official instructions on how to install the Compute Element.

Change directory to /etc/yum.repos.d/
<xterm2 root>
[root@grow-grid etc]# cd /etc/yum.repos.d/
</xterm2>

==== Install Epel ====
<xterm2 root>
[root@grow-grid yum.repos.d]# rpm -Uvh http://dl.fedoraproject.org/pub/epel/5/i386/epel-release-5-4.noarch.rpm
</xterm2>

==== Install YUM priorities ====
<xterm2 root>
[root@grow-grid yum.repos.d]# yum install yum-priorities
</xterm2>

Enable YUM plugins by adding this line in /etc/yum.conf under the [main] section.
<xterm2 root>
[root@grow-grid yum.repos.d]# vi /etc/yum.conf
</xterm2>
<file text /etc/yum.conf>
plugins=1
</file>

==== Install OSG repositories ====
<xterm2 root>
[root@grow-grid yum.repos.d]# rpm -Uvh http://repo.grid.iu.edu/osg-el5-release-latest.rpm
</xterm2>

==== Install CA Certificates ====
<xterm2 root>
[root@grow-grid yum.repos.d]# yum install osg-ca-certs
</xterm2>

==== Condor ====
<note important>Right now we have Condor installed via Rocks roll, there are some configuration errors happening and the is the way I want to install Condor once we have removed the roll.</note>
<xterm2 root>
[root@grow-grid yum.repos.d]# yum install osg-ce-condor
</xterm2>

==== Install Managed Fork ====
<xterm2 root>
[root@grow-grid yum.repos.d]# yum install globus-gram-job-manager-managedfork
</xterm2>

==== Configuration ====

===== Verification =====
<note>Each step in the verification requires you to create a proxy.</note>
==== Create a proxy ====
<xterm2>
[dsquires@grow-grid ~]$ grid-proxy-init
Your identity: /DC=org/DC=doegrids/OU=People/CN=Daniel Squires 809377
Enter GRID pass phrase for this identity:
Creating proxy .......................................... Done
Your proxy is valid until: Fri Jun 29 04:07:57 2012
</xterm2>

==== Run globusrun to ensure you are authorized. ====
<xterm2>
[user@grow-grid ~]$ globusrun -a -r grow-grid.its.uiowa.edu
GRAM Authentication test successful
</xterm2>

==== Attempt to run a job on the fork manager. ====
<xterm2>
[user@grow-grid ~]$ globus-job-run grow-grid.its.uiowa.edu /bin/hostname
GRAM Job failed because the job failed when the job manager attempted to run it (error code 17)
Details: condor_submit: Configuration Error Line 38 while reading global config source /opt/condor/condor_configure\n
</xterm2>
<note warning>
This error is unresolved!
</note>

==== Copy a file to the CE ====
This will not produce a result if successful.
<xterm2>
[dsquires@grow-grid ~]$ globus-url-copy file:///proc/cpuinfo gsiftp://grow-grid.its.uiowa.edu/tmp/cpuinfo-deleteme
</xterm2>

==== Copy a file from the CE ====
This will not produce a result if successful.
<xterm2>
[dsquires@grow-grid ~]$ globus-url-copy gsiftp://grow-grid.its.uiowa.edu/proc/version file:///tmp/version-deleteme
</xterm2>

Verify that the file was copied correctly.
<xterm2>
[dsquires@grow-grid ~]$ cat /tmp/version-deleteme
Linux version 2.6.18-194.3.1.el5 (brewbuilder@norob.fnal.gov) (gcc version 4.1.2 20080704 (Red Hat 4.1.2-48)) #1 SMP Fri May 7 01:43:09 EDT 2010
</xterm2>

Remove the tmp file
<xterm2>
[dsquires@grow-grid ~]$ rm -f /tmp/version-deleteme
</xterm2>

====== Notes ======


====== Contact Info ======
This Dokuwiki page is maintained by:\\
Daniel Squires\\
University of Iowa\\
Department of Computer Science\\
Email: <daniel-squires@uiowa.edu>