Reminder: New operating system default in HTC system on October 17

[chtc-users@xxxxxxxxxxx]

Greetings CHTC users,

This is a reminder for all users of our high throughput computing (HTC) system. Starting on October 17, CHTC-managed submit servers will change their default job requirements from allowing your jobs to run only on Scientific Linux 6, to allow your jobs to run on Scientific Linux 6 or CentOS 7. Unless you already know that your software will only run on CentOS 7 (in which case, a submit file "requirement" will override the default), your jobs should be unaffected by the change and should continue to run normally without taking any additional action. (Please let us know if you experience otherwise.)

For more details, including how to request a single operating system (if necessary) or how to test your jobs on each, see our initial email below.Â

Best,

Your CHTC team

---------- Forwarded message ----------
From: <chtc-users@xxxxxxxxxxx>
Date: Wed, Oct 4, 2017 at 3:56 PM
Subject: New operating system default in HTC system, October 17; please read
To: chtc-users <chtc-users@xxxxxxxxxxx>

Greetings CHTC users,

This message is for all users of our high throughput computing (HTC) system.

CHTC staff are continuing to upgrade the computers in our HTC system to a newer version of Linux, as described in this guide.

Up to now, HTC jobs submitted from CHTC-managed submit servers have required (by default) that they only run on execute servers with our Scientific Linux 6 operating system. Users have been able to also run on our newer operating system (CentOS 7) by opting in as we transition more execute servers to this new version. In two weeks, this default will change.Â

On October 17, all CHTC submit servers will be configured to allow submitted jobs to run on either operating system version unless you specify that they require only one of these.

CHTC jobs that have been running on Scientific Linux 6 will also be able to run on the newer CentOS 7 without errors (based upon our own tests and the experiences of users who have tried running on the newer CentOS 7). We anticipate that most users should be able to continue submitting jobs as usual without any changes.

If you are interested in testing your jobs on the new operating system (just to make sure they'll work), or if you otherwise know that your jobs cannot run on both operating systems, read on:

• If you want to test your jobs to make sure they will run successfully on CentOS 7, you can test a subset of your jobs by adding the following submit file line:
  requirements = (OpSysMajorVer == 7)
• If you already have a "requirements" statement specifying a specific "OpSysMajorVer", that requirement will override the defaults we set on the submit servers, so your jobs will only run on the OpSysMajorVer number(s) you have specified.
  
• For those who will need to run on only Scientific Linux 6 or only on CentOS 7 in the future, you will be able to specify a single operating system by using the same requirement described above, with the appropriate operating system version.Â
  

If you experience a situation where code that you've compiled on our Scientific Linux 6 servers (the current default) fails when running on CentOS 7 servers, please let us know immediately!Â

Email questions or concerns to chtc@xxxxxxxxxxx.

Best,
Your CHTC team

_______________________________________________
CHTC-users mailing list
CHTC-users@xxxxxxxxxxx
To unsubscribe send an email to:
chtc@xxxxxxxxxxx
https://lists.cs.wisc.edu/mailman/listinfo/chtc-users

--

Christina Koch -ÂResearch Computing Facilitator,Â

University of Wisconsin - Madison, Center for High Throughput Computing

Wisconsin Institute for Discovery; Advanced Computing Initiative; ACI-REF

email: ckoch5@xxxxxxxx // phone: (608) 316 - 4041 // calendar: tinyurl.com/ChristinaCHTC