Proper Usage of Front Ends
The front end machines are the interface to the the rest of the computing resources of the CRC. There are both faculty owned and public front ends, the majority of information found here will pertain to public front ends. The public front ends are shared by all of campus and external collaborators to perform a wide variety of tasks related to research.
There are 2 public facing (access without VPN or campus connection) front ends. If one machine appears slow, try the other one. The two public front ends are:
The primary interface to these machines is through SSH. To connect to either of these machines, you'd start either a terminal (Mac and Linux) or an ssh client on Windows. For Windows we recommend MobaXterm. You'd then either follow the instructions on the ssh client or enter the following command in a terminal, replacing "X" with the desired machine (1 or 2) and replacing "netid" with your Notre Dame NetID:
If you are having troubles logging in and have a new account, be sure to read the welcome email which was sent on the activation of your CRC account: you need to reset your ND password first to gain access. If you continue to have trouble logging in first check all spelling, be sure your ssh client and OS are updated/patched. If all else fails, notify us via email CRCSupport@nd.edu and please provide the following details: ND netid, which machine you're trying to connect to, your computer's Operating System (Windows, Mac, Linux, etc), and the ssh client you're using (Putty, MobaXterm, terminal, etc).
- Note:If you intend on using
HTCondorfor job submissions, the front end machine to connect to is
- If you need to compile code with infiniband support, connect to
crcfeib01.crc.nd.edu. Note that this machine requires a campus connection or VPN.
Utilizing Front Ends
Once connected to a front end, you may begin preparing jobs for submission to either UGE or HTCondor (on
condorfe.crc.nd.edu). There are a few important notes about operating within the front end environment:
- There will be other users connected to this machine, any disruptive behaviour will be addressed.
- Any task / process running longer than 1 (ONE) hour may be removed / killed by an administrator. Submit long running jobs to the batch system.
- Do not launch large mpi or smp processes on a front end.
- Front ends could be used for small debugging, if you have a job which requires more resources to be debugged submit it as a UGE job to the debug queue.
- More information on the queues and UGE can be found on the CRC UGE Environment page.
- When logged in, you will be within your user AFS space. Initially, there will be a few directories there. DO NOT remove your
Publicdirectory, this contains important login scripts.
- The default shell is
BASH. If you have an older account, your login shell may be
tcsh. If you'd like to request bash as your default, email CRCSupport@nd.edu.
- Software which is not included in an install of RHEL, can be accessed through the Modules.
- Small processing which is not disruptive/resource intensive can be done on the front ends. This is normally pre-processing or post-processing after completion of UGE jobs.
- All CRC systems are a Linux variant. For tip on Linux commands, see Linux Coding Cheat Sheets and More
The public front ends (01 and 02) are identical, both having the following:
2 x Intel(R) Xeon(R) CPU E5-2680 v3 @ 2.50GHz 12 cores per socket, 24 cores total, 1 thread per core. 256 GB of RAM Red Hat Enterprise Linux Server release 7.6 (Maipo) (subject to updating/upgrading)
When in doubt, the CRC Quick Start Guide is a good place to look for information on getting started with the CRC.
For submitting jobs to UGE, please see Submitting Batch/SGE jobs. Some example scripts can be found here: Sample User Scripts.
More sample scripts/submissions can normally be found on a module's page. Search for the module in question in the search bar on the top right of the page.