This article summarizes the key changes to how Quest users access and experience Quest after the March 2025 downtime.
The changes outlined below include deprecations. This means that although there is a new, preferred method, the old method will still continue to work until the next Quest downtime. It is important that users migrate their processes and update their bookmarks to ensure research continuity come the next downtime.
New Operating System Red Hat Enterprise Linux 8 (RHEL8)
The upgrade to the new operating system has the potential to impact all users.
Examples of Potential Impacts
- Compiled code: Codes compiled by users, especially those linking system or external libraries, may not work and might need recompilation after downtime.
- MATLAB: MATLAB versions before R2019b are not supported on RHEL8. These older modules and installations of MATLAB will be maintained to the limited extent possible. We encourage users to update the MATLAB module used in their workflows to matlab/r2024a if possible.
- R: All versions of R will launch on RHEL8, but user-installed packages, especially those that use system or external libraries, are not guaranteed to work. Such packages may need to be reinstalled after downtime.
- Python: Python packages, such as mpi4py, which compile "on-the-fly" should be tested to ensure that the package still imports and runs properly.
Users who experience issues with their workflows after downtime should contact quest-help@northwestern.edu for support.
Quest OnDemand
Quest OnDemand should now be accessed via the following URL: https://ondemand.quest.northwestern.edu.
The previous Quest OnDemand URL is now deprecated.
Quest Analytics Nodes
JupyterHub has been upgraded to 5.2.1 from 4.0.2.
The Quest Analytics nodes should now be accessed via the following URLs.
These URLs utilize a new load balancer which will improve user experience on the Analytics Nodes.
The previous Quest Analytics Nodes URLs are now deprecated.
Quest Login Nodes
Quest login nodes should now be accessed via SSH or FastX using the hostname login.quest.northwestern.edu. This hostname utilizes a new load balancer which will improve user experience on the log-in nodes.
Please note that the new hostname login.quest.northwestern.edu requires using Northwestern's GlobalProtect VPN when outside of the United States.
The previous hostnames (quest.northwestern.edu, quest.it.northwestern.edu, quser31.ci.northwestern.edu, quser32.ci.northwestern.edu, quser33.ci.northwestern.edu, quser34.ci.northwestern.edu) can still be used to connect to Quest login nodes but are now deprecated. These hostnames redirect to the new load balancer, so they also require using GlobalProtect VPN when outside of the United States.
Individual Quest login nodes can no longer be accessed directly from connections coming from outside of Quest. You can still SSH between any login nodes after you have connected.
Changes to FastX
The FastX Server version was upgraded from 3.2.77 to 3.3.65 . This upgrade should improve the experience for users of FastX and not change user workflows.
We will no longer be providing the KDE desktop as an option for a virtual desktop; the GNOME Desktop application is available as an alternative.
Quest Compute and GPU Nodes
To improve the stability and performance of Quest, we are dedicating more memory to the file system and Operating System processes on each compute node. This change requires reducing the maximum amount of memory that user jobs can access on each compute node. The reduction is dependent on the architecture/generation of the node.
For memory intensive workflows, we recommend reviewing your resource (memory + CPUs) request to ensure that it matches the new maximum schedulable memory.
New Compute Node Maximum Schedulable Memory
| Node Family Name |
Number of CPUs |
Amount of Schedulable Memory/RAM |
Partitions with these Nodes |
| quest10 |
52 |
166G (3.2G per core) |
short/normal/long/buyin |
| quest11 |
64 |
221G (3.5G per core) |
short/normal/long/buyin |
| quest12 |
64 |
221G (3.5G per core) |
short/normal/long/buyin |
| quest13 |
128 |
473G (3.7G per core) |
short/normal/long/buyin |
GPU Drivers
The NVIDIA drivers for all GPUs on Quest (both General Access and Buy-In) have been updated to version 570.86.15. These drivers are compatible with applications compiled against CUDA Toolkit <= version 12.8.
Scratch Storage
Scratch storage is now provided as 500 TB (5 per user) of flash (SSD) tier storage. The checkscratch utility is no longer available, instead please use dust to check disk utilization and find to find expiring files. See this article for usage.
KLC Nodes
KLC should now be accessed via SSH or FastX using the following hostnames:
- klc0201.quest.northwestern.edu
- klc0202.quest.northwestern.edu
- klc0203.quest.northwestern.edu
- klc0301.quest.northwestern.edu
- klc0302.quest.northwestern.edu
- klc0303.quest.northwestern.edu
- klc0304.quest.northwestern.edu
- klc0305.quest.northwestern.edu
- klc0306.quest.northwestern.edu
- klc0307.quest.northwestern.edu
The previous KLC hostnames can still be used with SSH or FastX but are now deprecated.
- klc0201.ci.northwestern.edu
- klc0202.ci.northwestern.edu
- klc0203.ci.northwestern.edu
- klc0301.ci.northwestern.edu
- klc0302.ci.northwestern.edu
- klc0303.ci.northwestern.edu
- klc0304.ci.northwestern.edu
- klc0305.ci.northwestern.edu
- klc0306.ci.northwestern.edu
- klc0307.ci.northwestern.edu
If you use SSH with the deprecated KLC hostnames, you will receive an error that says "host key verification failed." You can fix this issue by deleting your known_hosts file and trying again
rm ~/.ssh/known_hosts
or by switching to the new preferred hostname for that KLC node.