Change of default operating system

On Thursday 27 June at 07:00, Ubuntu will become the new default operating system of Euler:

  • All existing SSH connections to the login nodes of Euler will be terminated
  • From this point, all new SSH connections to euler.ethz.ch will lead to the new Ubuntu login nodes
  • The old CentOS login nodes will remain accessible for a few days at login-centos.euler.ethz.ch
  • The beta Ubuntu login nodes will remain accessible for a few weeks at login-beta.euler.ethz.ch
  • Depending on the configuration of your SSH client, you may receive a warning when you try to login. You can prevent this warning by proactively adding the lines

euler.ethz.ch ssh-ed25519 AAAAC3NzaC1lZDI1NTE5AAAAIHxvQkvInDhLK2K1kpm9SVuE6JFIS0Js2vxwH7mFA0Wn
login-centos.euler.ethz.ch ssh-ed25519 AAAAC3NzaC1lZDI1NTE5AAAAIHxvQkvInDhLK2K1kpm9SVuE6JFIS0Js2vxwH7mFA0Wn
login-beta.euler.ethz.ch ssh-ed25519 AAAAC3NzaC1lZDI1NTE5AAAAIHxvQkvInDhLK2K1kpm9SVuE6JFIS0Js2vxwH7mFA0Wn

to the file ~/.ssh/known_hosts on your local computer. If any of the lines is already in your known_hosts file, then don't add this line. For more information please check the wiki page Host keys for Euler login nodes.

Please note that the new Ubuntu environment is not backward-compatible with CentOS. If you have not done so already, please check and if necessary recompile your applications in the new environment, as described here and here.

If you have some automated script or workflow that opens an SSH connection to Euler to run some program, please make sure that this program is compatible with Ubuntu. If you do not have time to check and/or recompile this program before Thursday morning, please modify your script to open an SSH connection to login-centos.euler.ethz.ch instead of euler.ethz.ch. Keep in mind that this is only a temporary solution that will stop working when the CentOS part of Euler is definitively turned off.