Table of Contents

External sources

The following external sources provide a great deal of information about HPCs. If you are new to HPCs, please use these sources (and other information on the web) to fill up the knowledge gaps:

• https://hpc-wiki.info/hpc/HPC_Wiki

Using the shell

To access and use AWI's HPC systems login via a terminal is needed, using ssh.

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• https://www.ssh.com/ssh/keygen

Example:

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Albedo

Here is an example for my (Natalja's) desktop a user named "user" and a desktop named "desktop" connecting to NEC SX-ACE StanAlbedo. Please replace username and remote machine accordingly!

• Generate a key on your local desktop or whatever machine you want to connect to stan0 albedo0 and stan1albedo1

  rakowsky@binf02l006user@desktop:~$ ssh-keygen -t ed25519 -a 100 -f ~/.ssh/id_rsa_awihome-stan -t rsa -b 4096

  Here, we stick to rsa to be on the safe side to generate a portable key. For more recent machines, ssh.com recommends ecdsa: ssh-keygen -t ecdsa -b 521

  ed25519_albedo

  You are asked for a passphrase. A passphrase increases the security in case your account is hacked or your notebook gets lost, and it is a must for connections between systems at different locations, e.g., from AWI to HLRN or from home to AWI. Please use a strong passphrase to secure your key.
  Two files are generated

  1. the private key ~/.ssh/id_rsaed25519_awihome-stan albedo remains on your local machine,

  2. the public key ~/.ssh/id_rsaed25519_awihome-stanalbedo.pub is copied to the remote machine.

• Our recommendation is to have a pair of private+public keys for each local+remote connection. It helps to keep an overview and a good naming scheme helps to prevent the danger of overwriting an existing key.
• Make sure you are connected to the AWI network (via ethernet or VPN)

• Copy the public key to StanAlbedo, here to stan1albedo1, this also makes the key available on stan0albedo0, as they share the home directory:

  rakowsky@binf02l006user@desktop:~$ ssh-copy-id -i ~/.ssh/id_rsaed25519_awihome-stanalbedo.pub rakowsky@stan1<your_username>@albedo1.dmawi.de

  For some destinations, to increase the security, the public key has to be uploaded in a web portal, and it is not placed in your remote home directory.  For Albedo the command above is all you need.

• Log in to stan0 albedo0 or stan1 albedo1 with

  rakowsky@binf02l006user@desktop:~$ ssh -i ~/.ssh/id_rsaed25519_awihome-stanalbedo -Y rakowsky@stan0<your_username>@albedo0.dmawi.de

  
  

• Or, for convenience, add an entry to ~/.ssh/config on your local desktop. Generate this file, if not yet present.

  rakowsky@binf02l006user@desktop:~$ cat ~/.ssh/config Host stanalbedo0    Hostname Hostname stan.awialbedo0.dmawi.de    IdentityFile IdentityFile ~/.ssh/id_rsaed25519_awihome-stanalbedo User rakowsky user <your_username>

  and log in with

  rakowsky@binf02l006user@desktop:~$ ssh -Y stanalbedo0

For more details about ssh have a look at SSH.