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Migrating to the New Operating System

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This page will continue to be updated with new information. Check back regularly for updates.

Recommendations to users

In order to transition to the upgraded system, please follow these steps:

  1. If you SSH to the HPCC through VS Code or proxy jumps, follow the instructions below.
  2. Use development nodes that have been upgraded to Ubuntu.
  3. Change the module names and versions of the software you are using to match the new system.
    • Note: The module names will have changed in the upgraded system, and not all versions will be carried over from the current system
    • Review the Available Software page or use module spider <module_name> or module avail to find a module you need
  4. Reinstall any Python virtual environments.
  5. Try running a small test of your existing code on the development nodes, replacing the module names with those available on the upgraded system.
  6. Try running a small test of your existing code with a SLURM job.
  7. If your code no longer runs as expected it is likely incompatible with the new operating system.
    1. If you compile your own code or have built/installed packages in R or Python, rebuild using the modules available on the upgraded system. We recommend doing this in a separate location so your existing code will continue to work.
    2. If you use R, consider reinstalling your R packages.
    3. If you use Conda, consider reinstalling Conda and your environments.
  8. Test your existing codes and scripts with our backwards compatibility helper commands as a backup.

If you run into problems at any of these steps, please contact us using the subject "OS Upgrade 2024" with a description of the problem and any files necessary to reproduce it.

Unable to login via VS Code or receiving "WARNING: REMOTE HOST IDENTIFICATION HAS CHANGED!" message

Applies to VS code

The errors below will stop most users from using VS Code to SSH into the HPCC, but will be hidden in VS Code's SSH output. Please try following the instructions below and try logging in again.

When logging in to upgraded nodes using SSH keys and proxy jumps, you may receive a message like:

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@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@
@    WARNING: REMOTE HOST IDENTIFICATION HAS CHANGED!     @
@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@
IT IS POSSIBLE THAT SOMEONE IS DOING SOMETHING NASTY!
Someone could be eavesdropping on you right now (man-in-the-middle attack)!
It is also possible that a host key has just been changed.
The fingerprint for the RSA key sent by the remote host is
SHA256:rydhZ58BeXsXgWQisWlbH6E0IFG+2+LSxC9a7OfZBro.
Please contact your system administrator.
Add correct host key in ~/.ssh/known_hosts to get rid of this message.
Offending RSA key in ~/.ssh/known_hosts:6
You can use following command to remove the offending key:
ssh-keygen -R dev-amd20 -f ~/.ssh/known_hosts
Host key for dev-amd20 has changed and you have requested strict checking.
Host key verification failed.

or:

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The authenticity of host 'dev-amd20 (<no hostip for proxy command>)' can't be established.
RSA key fingerprint is SHA256:rydhZ58BeXsXgWQisWlbH6E0IFG+2+LSxC9a7OfZBro.
This key is not known by any other names.
Are you sure you want to continue connecting (yes/no/[fingerprint])?

These messages are expected as the keys used to verify the "identity" of the development nodes have changed from what your computer has used before. To fix the first error, run the command

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ssh-keygen -R <dev-node-name> -f ~/.ssh/known_hosts

on the command line on your local computer, not the HPCC. Alternatively, you can also delete the file ~/.ssh/known_hosts to reset all host keys. This will result in receiving the second message anytime you SSH to any other computer (even ones outside of ICER, like GitHub) until you've accepted the connection again.

To accept the new connection and fix the second error, enter "yes" and hit enter.