Specifying the Remote Spawn Command as RSH or SSH (Linux)

An important step in using a high-performance cluster is setting up authentication across machines in such a way that the machines can be accessed without a password. By default, Maxwell 2D and Maxwell 3D use SSH authentication on Linux to spawn commands on the remote machines but also support RSH. The selection of which to use is made on the Options tab of the Tools > Options > HPC and Analysis dialog.

SSH

You will need to set up passwordless access to useMaxwell on a Linux cluster with SSH or RSH. In general, for SSH, this is accomplished as follows:

  1. Verify that you have working SSH servers and clients on your machines.
  2. Verify that the server will accept passwordless logins. You may need to edit the /etc/ssh/ssh_d file to allow RSAAuthentication and PubkeyAuthentication.
  3. Generating keys on the client system using the ssh-keygen program. Do not use a passphrase so that you can access the machine without a password.
  4. Copy the public key generated in step 1 from the ~/.ssh directory to the server. The easiest way to transfer the keys is to use the ssh-copy-id program. Alternately, you can use any file transfer utility. If the server already has a list of existing keys for other clients add the new public key to the list.
  5. Test the connection. Log in to the client machine using the username that you used to create the identity keys. Open a new shell terminal and attempt to open an SSH login session. For example, type: ssh 192.168.0.4 (where the IP address is the address of the machine you are attempting to connect to). The server should allow you to login without requesting a password.

RSH

If you choose to use RSH, you will need to make sure RSH is installed on all the machines and set the machines up so that you are not prompted for a password. There are different ways to set up password-less RSH, so be sure to see the documentation for your machines and network for detailed instructions.

Machine access using RSH without a password is often set up by editing the /etc/hosts.equiv file and adding entries for the hosts you would like to use without a password. This file lists hosts and users that are granted "trusted" access to the system.

If you look at the contents of the /etc/hosts.equiv file you should have something similar to the following:

job1.n1.com
job2.n1.com
job3.n1.com

The machines job1, job2, and job3 can connect without a password. You may also need to verify that the files /etc/hosts.allow and /etc/hosts.deny are empty. See your local documentation for detailed instructions and troubleshooting suggestions.

Related Topics 

Setting HPC and Analysis Options for Maxwell and RMxprt Designs