Before You Begin

C H A P T E R 3

Before You Begin

This chapter provides miscellaneous information about the runtime environment that you should know before you begin to use it. It contains the following sections:

Prerequisites

Command and Man Page Paths

Core Files

Setting Up a known_hosts File

Prerequisites

If your program uses Sun HPC ClusterTools components, compile and link it on a cluster that contains the Sun HPC ClusterTools software.

It is strongly suggested that you use the Sun HPC ClusterTools 8.1 wrapper compilers to compile applications. These wrapper compilers add the appropriate compiler and linker flags to the command line and call the underlying compiler and linker for you. Wrapper compilers are available for C, C++, Fortran 77, and Fortran 90.

For more information about compiling MPI applications, see the “Compiling MPI Applications” FAQ at:

http://www.open-mpi.org/faq/?category=mpi-apps

Command and Man Page Paths

Sun HPC ClusterTools commands typically reside in the following directories:

Solaris OS: /opt/SUNWhpc/HPC8.1/sun/bin

Linux:

/opt/SUNWhpc/HPC8.1/gnu/bin for the GNBU compiled version

/opt/SUNWhpc/HPC8.1/sun/bin for the Sun Studio compiled version

You can run the Sun HPC ClusterTools software directly from the directory in which yourClusterTools commands are installed, or you may add the directory to your PATH or set the PATH environment variable.

The man pages for Sun HPC ClusterTools commands reside in the /opt/SUNWhpc/man directory.

The Sun HPC ClusterTools files typically reside in /opt/SUNWhpc/HPC8.1.

Note - The examples in this manual refer to the default location for the Solaris and Sun Studio compiled Linux binaries. Be sure to use the path name that corresponds to your operating system and ClusterTools version.

Setting Up Your Path

To Set Up Your Path for the Solaris OS and the Sun Studio Compiled Linux Version

For example, if you installed the Sun HPC ClusterTools 8.1 software for the Solaris OS in the default location of /opt/SUNWhpc/HPC8.1/sun/bin, you would add this location to your PATH as shown in the following example:

% setenv PATH /opt/SUNWhpc/HPC8.1/sun/bin:${PATH}

The setenv command prefixes the PATH on both the local and remote hosts with /opt/SUNWhpc/HPC8.1/sun/bin.

Note - If you are using the Solaris OS version of the ClusterTools software, you can also activate the Sun HPC ClusterTools software by running the ctact utility. Activation sets up the symbolic links so that you can run the software from any location on the host, not just the location where you installed it. For more information about activating the software, refer to the Sun HPC ClusterTools 8.1 Software Installation Guide.

To Set Up Your Path for the GNU Compiled Linux Version

For example, if you installed the GNU compiled version of the Sun HPC ClusterTools 8.1 software for Linux in the default location of /opt/SUNWhpc/HPC8.1/gnu/bin, you would add this location to your PATH as shown in the following example:

% setenv PATH /opt/SUNWhpc/HPC8.1/gnu/bin:${PATH}

The setenv command prefixes the PATH on both the local and remote hosts with /opt/SUNWhpc/HPC8.1/gnu/bin.

Core Files

Core files are produced as they normally are in the Solaris environment. However, if more than one process dumps core in a multiprocess program, the resulting core file may be overwritten in the same directory. Use coreadm(1M) to control the naming and placement of core files.

To disable the core dump, use the limit(1) command. You can use the following command in the C shell:

% limit coredumpsize 0

Setting Up a `known_hosts` File

If you are using ssh to connect to your remote nodes, you must set up your ~/.ssh/known_hosts file to contain the remote nodes’ host key, especially if you try to run on a cluster with many nodes for the first time.

Setting up the known_hosts file avoids having to respond to the following prompts when running mpirun to the remote nodes:

% /opt/SUNWhpc/HPC8.1/sun/bin/mpirun -host host04,host05,host06 hostname
 
The authenticity of host ’host04 (129.148.9.88)’ can’t be established.
RSA key fingerprint is ff:73:0e:91:7b:19:e6:a3:9a:f8:6c:07:0a:ce:1a:f2.
Are you sure you want to continue connecting (yes/no)? 
The authenticity of host ’host05 (129.148.9.84)’ can’t be established.
RSA key fingerprint is 11:f6:bd:f7:a9:5b:05:ab:73:ee:81:0f:c8:2f:ac:cb.
Are you sure you want to continue connecting (yes/no)? 
The authenticity
of host ’host06 (129.148.9.86)’ can’t be established.
RSA key fingerprint is c1:24:c4:9c:86:33:25:3b:08:59:12:b5:1b:9d:b2:c6.
Are you sure you want to continue connecting (yes/no)?
Host key verification failed.
yes
Please type ’yes’ or ’no’: yes
Please type ’yes’ or ’no’: yes
Please type ’yes’ or ’no’: yes
Please type ’yes’ or ’no’: yes
Please type ’yes’ or ’no’: yes
Please type ’yes’ or ’no’: yes
...

Prerequisites

Command and Man Page Paths

Setting Up Your Path

Core Files

Setting Up a known_hosts File

Setting Up a `known_hosts` File