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Table of Contents
Connecting to the CHPC
The CHPC hosts three systems of supercomputers:
- SUN
- Westmere cluster (Sun & Dell)
- Nehalem cluster
- Harpertown cluster
- M9000 SMP
- Nvidia Quadro visualization node
- GPU cluster (Supermicro)
- 9x Nvidia C2070 “Fermi” cluster
- 15x Nvidia C1060 “Telsa” cluster
Each system has a single login node which is connected to the Internet and allows connections to the individual supercomputers of each system.
Logging In
Connections to the login nodes of the CHPC machines is via the ssh protocol. To connect use
ssh username@sun.chpc.ac.za
where login-node is replaced by the hostname for the login node of the system you wish to connect to, and username is replaced by the user name assigned to your account at the CHPC.
Hostnames
The hostnames for all CHPC login nodes are listed below. If you are within CHPC the DNS server will return RFC 1918 addresses, if you are outside you will get globally routeable addresses.
| System | Host Name | |
|---|---|---|
| SUN | Primary address | sun.chpc.ac.za |
| GPU | Primary address | gpu.chpc.ac.za |
Transferring Files
Use scp or sftp to transfer files to or from your home directory on the CHPC systems. For example
scp src.tar.gz username@sun.chpc.ac.za:~/scratch/
to copy the file src.tar.gz to your work directory on the SUN cluster.
MS Windows
Should you be using a MS Windows computer to connect to the CHPC we suggest you download and install the open source PuTTY and WinSCP clients:
| Windows Application | Provides | Home page | |
|---|---|---|---|
| PuTTY | ssh | http://www.chiark.greenend.org.uk/~sgtatham/putty/ | download |
| WinSCP | scp/sftp | http://winscp.net/ | download |
ssh keys
The best way to connect via ssh is to create ssh keys which authenticate you instead of your password.
First create your private and public keys on your main work computer (which we assume is a desktop or laptop computer running Linux)
ssh-keygen -t dsa
This creates two new files in your .ssh directory
| id_dsa | your private key |
| id_dsa.pub | the corresponding public key |
It is the latter file that you need to add to the .ssh/authorized_keys file in your home directories on the CHPC login nodes (SUN or IBM Blue Gene).
From a recent Linux distribution you can simply do this :-
ssh-copy-id username@sun.chpc.ac.za
From older Unix setups you might have to do this :-
cat ~/.ssh/id_dsa.pub | ssh username@sun.chpc.ac.za "cat >> .ssh/authorized_keys; chmod 0700 .ssh; chmod 0600 .ssh/authorized_keys"
And the next time you ssh or scp to the CHPC login node you won't have to use your password!
(Notice that you need to change the permissions of the .ssh directory and the authorized_keys file on the login nodes to make them private and readable by you only before ssh will use the new public key.)
