Stanage FAQ and Gotchas

This section contains important information about the usage of the Stanage cluster and any significant changes from expected behaviour on previous University of Sheffield HPC clusters.

Your first connection to Stanage requires the VPN

Connections to the Stanage cluster without the VPN enabled require the use of TOTP MFA. As this requires setup, your first connection to the cluster must take place with the VPN connected (including on campus access from devices on wired ethernet).

Click on the following link for the instructions to set up: TOTP MFA.

Resetting Stanage TOTP multifactor authentication

If you need to add your TOTP multifactor authentication to another phone you can show your QR Code again by logging into the cluster and running the commands:

flight start
flight mfa show

If you need to reset your TOTP multifactor authentication as you have lost a device which had the TOTP account on it, you can generate a new seed key and matching QR code with:

flight start
flight mfa generate --force

DUO authentication

As DUO authentication is not yet implemented on Stanage, users should be aware that where you may normally be prompted by DUO MFA this may not occur. This may change in future however the current MFA in use is TOTP based.

Graphical applications

At present, we only provide very limited support for running graphical sessions on Stanage. Please see Graphical sessions on Stanage

Poor performance with OpenMPI 4.1.1

Current installations of OpenMPI 4.1.1 have poor performance over Omnipath which is still under investigation. These versions of OpenMPI will be in use for the foss-2021 Easybuild toolchain and should be avoided.

Shared research area directories

Shared research areas are available on the Stanage cluster upon request. For details on this please see our page on Shared (project) directories.

My tmux or screen session is missing from the login node?

The Stanage cluster uses two login nodes in a active-backup configuration. This means when you connect via stanage.shef.ac.uk you will actually connect to one of the two login nodes, stanage-login1.shef.ac.uk or stanage-login2.shef.ac.uk depending on which is currently the active login node.

If you disconnect from the cluster and return at a later time, you may not connect back to the same login node and won’t be able to access the session you left running. If you are going to make use of tmux or screen sessions on Stanage, you should choose one of the two login nodes and consistently directly connect via it.

It is also possible that after a maintenance period or a login node reboot, that all running tmux or screen sessions will have been terminated as part of this and you will need to recreate your sessions. If you think this might have happened then you can check if the given login node’s uptime with the uptime command to see if there has been a recent reboot.