== Intall mpich2 ==
=== 1. Testbed Introduction ===
 * VMware Workstation 5.0
 * Create three nodes, client-01 ~ client-03, all with 5GB HD and 128MB memory.
 * The OS on these 3 nodes is Ubuntu-7.10-server
 * hostname and IP are:
  * client-01 192.168.180.131
  * client-02 192.168.180.132
  * client-03 192.168.180.133
=== 2. Getting Start to intall mpich2 ===
 * '''Step 1''' : Modify /etc/hosts
  * Assume that we got 3 machines in our testbed, now we have to edit /etc/hosts on each node.[[BR]]
    Here is the example of client-01. So does the other two nodes.
{{{
root@client-01:~# cat > /etc/hosts << "EOF"
> 127.0.0.1 localhost
> 192.168.180.131 client-01
> 192.168.180.132 client-02
> 192.168.180.133 client-03
> EOF
}}}
  * Check the /etc/hosts contents, it should be like this.
{{{
root@client-01:~# cat /etc/hosts
127.0.0.1 localhost
192.168.180.131 client-01
192.168.180.132 client-02
192.168.180.133 client-03
}}}
  * Notice that if there is __127.0.0.1 client-01__ in /etc/hosts, it must be deleted.

 * '''Step 2''' : Download and Install mpich2
  * We use mpcich2-1.0.7rc1 for example.
{{{
root@client-01:~# wget http://www.mcs.anl.gov/research/projects/mpich2/downloads/tarballs/mpich2-1.0.7rc1.tar.gz
root@client-01:~# tar -zxvf mpich2-1.0.7rc1.tar.gz
cd mpich2-1.0.7rc1/
}}}
  * You could choose the install location as you wish, but all the nodes must have the same install location!! [[BR]]
    We use ''/opt/mpich2'' here for example.
{{{
root@client-01:~/mpich2-1.0.7rc1# ./configure preifx=/opt/mpich2
}}}
   * If there are errors when configuring mpich2, you may need some packages or libraries such as c/c++ compiler.[[BR]]
     Try this :
{{{
root@client-01:~/mpich2-1.0.7rc1# apt-get install build-essential
}}}
  * compile and install
{{{
root@client-01:~/mpich2-1.0.7rc1# make
root@client-01:~/mpich2-1.0.7rc1# make install
}}}

 * '''Step 3''' : Check if the Installation is Successful
  * Try these commands to see if the mpich2 have been installed correctly.
{{{
root@client-01:~/mpich2-1.0.7rc1# which mpd
/usr/local/bin/mpd
root@client-01:~/mpich2-1.0.7rc1# which mpicc
/usr/local/bin/mpicc
root@client-01:~/mpich2-1.0.7rc1# which mpiexec
/usr/local/bin/mpiexec
root@client-01:~/mpich2-1.0.7rc1# which mpirun
/usr/local/bin/mpirun
}}}
  * If there is nothing showed on the screen when enter ''which xxxx'', you probably need to set your environment variables.
{{{
root@client-01:~/mpich2-1.0.7rc1# export PATH="$PATH:/opt/mpich2/bin"
}}}

 * '''Step 4''' : Add New Configuration Files
  * Add ''mpd.host file'', you could put it anywhere in your system.
{{{
root@client-01:~/mpich2-1.0.7rc1# touch mpd.hosts
root@client-01:~/mpich2-1.0.7rc1# cat > mpd.hosts << "EOF"
> client-01
> client-02
> client-03
> EOF
}}}
  * Check if the content in mpd.hosts is correct.
{{{
root@client-01:~/mpich2-1.0.7rc1# cat mpd.hosts
client-01
client-02
client-03
}}}
  * Add ''/etc/mpd.conf'', there is only one line in it.
   Notice that all the nodes must have the same password.
   We use "this_is_password" for example here.
{{{
root@client-01:~/mpich2-1.0.7rc1# touch /etc/mpd.conf
root@client-01:~/mpich2-1.0.7rc1# cat > /etc/mpd.conf << "EOF"
> secretword=this_is_password
> EOF
}}}
  * Change the file properties to 600 for security consideration.
{{{
root@client-01:~/mpich2-1.0.7rc1# chmod 600 /etc/mpd.conf
}}}


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