Reinstating user password-less access to compute nodes

There are occasionally in a cluster environment that users accidentally delete their head node SSH keys and later cannot submit their jobs to the queue or their MPI jobs cannot scale beyond 1 node. The system you will see when you turn on the verbose method

To conduct a quick test,

# ssh -v remote-host

you will see an errors similar to  such as those below:

debug1: Unspecified GSS failure.  Minor code may provide more information
Unknown code krb5 195


debug1: Miscellaneous failure
No credentials cache found

To reinstate the password-less access to compute nodes, you have to do the following. First thing first, please do backup files at your ~/.ssh/

Step 1: Regenerate the SSH keys
SSH Login without Password

Step 2: Append the public keys ~/.ssh/ and put into the ~/.ssh/authorized_keys

# cd ~/.ssh/
# cat >> authorized_keys
# chmod 400 /home/myuser/.ssh/authorized_keys

Step 3: Try ssh into the compute nodes. It should be clear password-less access to all nodes.


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