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Center for High Throughput Computing

The HTC System is Transitioning to a Newer Linux Version (CentOS 7)

CHTC staff are in the midst up upgrading the default operating system on our high throughput compute system from Scientific Linux 6 (SL6) to a newer and slightly different Linux version - CentOS 7. We will update this page with more information as we pass major transition milestones.

1. Current Status

We have started converting our computers to the new operating system, in a gradual process over the course of the next several months. As of October 3, 2017, about 35% of our HTC system is running CentOS 7. We plan to be at 50% by mid-November 2017.

2. Using Both Operating Systems

As of October 17, CHTC-managed submit servers default to allow jobs to run on both operating systems, unless a user indicates otherwise in the submit file, which will override the default (see below).

Most jobs in our high throughput system were compiled and run on our old operating system (Scientific Linux 6) and should be able to run effectively on both operating systems without any issues. If you experience any issues with your jobs that you cannot diagnose, please let CHTC facilitators know immediately by emailing chtc@cs.wisc.edu.

3. Requesting a Specific Operating System

If your job requires our newer operating system, you can override the default requirement that permits jobs to run on both operating systems. Note that most jobs can run on both SL6 and CentOS 7 and requesting a single operating system will restrict your jobs from accessing the full capacity of CHTC that they could use. Running on just CentOS 7 should only be necessary for code compiled on CentOS 7 (including newer versions of R) or Docker jobs. If this applies to you and you truly need to run on one operating system, read on.

To request that your jobs run on CentOS7 only add the following requirements line to your submit file:

requirements = (OpSysMajorVer == 7)

In the rare case that your job requires to run only on Scientific Linux 6, you can use the same requirement with a 6 instead of a 7.

Combining Requirements

Does your job already have a requirements statement? If so, you can add the requirements above to the pre-existing requirements by using the characters &&. For example, if your jobs already require Gluster:

requirements = (Target.HasGluster == true) 
You can add the requirements for using CentOS 7 like so:
requirements = (Target.HasGluster == true) && (OpSysMajorVer == 7)