What is changing?
Beginning January 7, 2020, users will no longer be able to use SSH to access aci-i.aci.ics.psu.edu.
All users utilizing SSH should use the hostname aci-b.aci.ics.psu.edu.
How do I make the change?
For most users, making the switch should be simple and straightforward. Just follow these three steps when using an SSH client to access the ICDS-ACI system:
1. Use the hostname aci-b.aci.ics.psu.edu.
From here you can access your files, check the status of a job, submit a job—any of the tasks you are accustomed to doing with an SSH connection.
2. Remember that you need to request resources for your job with a “qsub” or “interact” command.
When you first access to aci-b.aci.ics.psu.edu, remember you’re on a login node which isn’t designed to handle compute jobs. Using a QSUB statement ensures that your job runs on compute nodes where it belongs. Without the QSUB statement, you’re tying up resources that need to be shared with other users, and your job is subject to cancellation by system administrators.
For convenience, ICDS-ACI engineers are providing a simple “interact” command that will spawn a dedicated resource for your interactive job needs on the open queue. Simply type “interact” after logging into aci-b and you will be routed to the proper place to do interactive work.
3. If you used X11 forwarding to access remote graphical applications, consider using Open OnDemand instead.
While you can use X11 forwarding when logging into aci-b.aci.ics.psu.edu, you may find Open OnDemand to be a simpler option. You can access Open OnDemand using a web browser to: PORTAL.ACI.ICS.PSU.EDU.
If you need more help making this change, contact the i-ASK helpdesk. The i-ASK helpdesk will also be holding special office hours to answer any of your questions on this topic on Tuesday December 10, 2:00-3:00PM in 223 Computer Building, or by appointment.
Why is this happening?
The compute resources at aci-i.aci.ics.psu.edu are earmarked for use with Open OnDemand, our web-based graphical interface. To ensure the equitable use of this limited, shared resource, ICDS is directing all SSH users to the aci-b.aci.ics.psu.edu resources which are better equipped to handle these larger jobs.