FAQ

DUNE Computing Newsletter for July-August 2026

The purpose of this newsletter is to inform the collaboration of recent and upcoming changes in computing. We’re in the middle of an ‘exciting’ time for computing as we’re constantly adapting to new operating systems and authentication methods. This means there are frequent changes that affect all DUNE users. We offer tutorials, the wiki, and a FAQ page, but those move more slowly so we’re trying this newsletter as a way to bridge the gap between permanent documentation and real-time announcements.

You can find newsletters at https://wiki.dunescience.org/wiki/Computing_Newsletters.

If you want computing news and have questions, remember to join the DUNE Slack and the #computing-announcements and #computing-questions channels. (And if you know an answer, please help out.)

Slack: #computing-questions, #computing-announcements, #computing_training_group

New features and projects

September 10, 2026 basics tutorial at noon (FNAL time).

A three hour DUNE Computing Basics tutorial will take place via Zoom on Thursday, September 10th. If you plan to attend, please fill out the survey so we can contact you with updates.

A computer account at Fermilab or CERN is required, if you have not used those facilities before, please do the setup before the tutorial.

October DUNE PHLEX workshop in India

https://dune-tech.rice.edu/RGI_DUNEworkshop/

October 26-30, 2026 at the Indian Institute of Science, Bengaluru, India

DUNE collaboration members, physicists, computer scientists, and software engineers will discuss PHLEX adoption through hands-on sessions and AI/ML libraries. Eligibility: participants must be from an Indian institution of higher education; registration will be open until September 5th, 2026. We are also looking for expert lecturers; travel support for lecturers will also be provided. This will be an excellent opportunity to engage directly with attendees, strengthen collaborations, and advance the work of the PHLEX Adoption Task Force. As DUNE moves toward PHLEX implementation, the workshop offers a timely opportunity to build momentum and coordinate support.

Enhanced Dataset searches

The DUNE data catalog webpage ​​https://dune-tech.rice.edu/dunecatalog/ has incorporated new features. Users can search a dataset and open any file’s detail page, where they can view its Rucio replica info, metadata, and provenance, with a one-click copy of the replica info for use in interactive jobs. The catalog also supports advanced searches from the Other tab, including MQL queries with native wildcard syntax and queries to the conditions DB (ProtoDUNE-HD and VD), which can be filtered by run, by momentum, or by start/stop date or gain. We have also updated our documentation here in docDB

New Tutorial chapter on Interactive computing resources

We’ve added a new basics chapter describing the general interactive computing resources (Interactive Computing Resources)

Heads-up Redmine migration

Most of DUNE uses Github or wiki.dunescience.org for documentation and code, but some codes are still in the RedMine system. It was temporarily available only onsite at Fermilab in August due to a security problem with the version Fermilab was running. This has been fixed but it is a good idea to consider migrating any RedMine code/documentation to Github/wiki.dunescience.org. We’ll be communicating pointers on how to do this as we find out ourselves.

Reminder – VNC instructions

Many people like to use VNC’s to connect to the gpvms. This allows you to, for example, open root windows more quickly. Unfortunately, many VNC methods (often gnome) launch a full desktop environment which spawns hundreds of unused processes. If your processes cause significant resource wastage, expect a slack or email message from management asking you to kill all your processes and to switch your VNC methods.

Ken Herner has written up how to use **IceWM **instead of gnome. We ask that everyone move to this method as it does not bog down our systems.

https://wiki.dunescience.org/wiki/DUNE_Computing/Using_VNC_Connections_on_the_dunegpvms

describes how to set up the IceWM on your gpvm and also provides a script from Dom Brailsford that you can use to set up your VNC system.

source /nashome/d/dbrailsf/setupVNCNew.sh

Spack updates for LArSoft and Phlex

There has been a lot of work on spack builds for DUNE software for use on AL9. Please join the #spack channel in Slack for frequent updates and to report issues. You can submit issues and view status at https://dune.github.io/dune-spack-project/. We are now up to v1.2.2 for spack itself and 0_3_2 for Phlex. For convenience, there are generic setups but they point to versioned instances. There is also a Spack Cheat Sheet with common commands.

The lar version in spack is now pretty complete. Please test running lar from an AL9 window and report issues at https://dune.github.io/dune-spack-project/

To get larsoft
source /cvmfs/dune.opensciencegrid.org/spack/setup-env.sh
echo "Activate dune-prototype"
spack env activate dune-prototype
To get phlex (our new framework for testing)
source /cvmfs/dune.opensciencegrid.org/spack/setup-env.sh
echo "Activate dune-phlex-prototype"
# currently phlex-0_3_2-prototype
spack env activate dune-phlex-prototype

Updates and reminders from previous months

Reminder: Official Datasets

The Production Group makes official datasets. The Rice group has created a website for finding them. There are also command line tools for exploring further. See the tutorial for details or go straight to the website to find your samples.

Reminder of Wednesday down times

A reminder that the Fermilab compute nodes and disk servers undergo monthly maintenance on the 3rd Wednesday of each month. Systems are partially unavailable for 3-6 hours, which leads to things not working.

Reminder: Using SL7

Just a reminder that building larsoft still requires Scientific Linux 7 in a container. You can find sample scripts for setting up your container here.

Tokens

Tokens are the new way to authenticate to access dCache disk, our data catalogs (rucio) and submit batch jobs (justin and jobsub). On SL7, follow these instructions. On AL9, it still depends on which Spack environment you are using. The recent dune-prototype spack environment (above) can make tokens using justIN get-token. We suggest you upgrade to that one.

If you just want to access files via root or xrdcp and don’t need rucio or justin you can use this method to get an interactive token.

htgettoken -i dune --vaultserver htvaultprod.fnal.gov -r interactive 
export BEARER_TOKEN_FILE=/run/user/`id -u`/bt_u`id -u`
export X509_CERT_DIR=/cvmfs/oasis.opensciencegrid.org/mis/certificates

**Tips and Tricks: **

Want to read HDF5 files with LArSoft?

for now you need to load a special library on the same line as your lar command.

LD_PRELOAD=$XROOTD_LIB/libXrdPosixPreload.so lar -c standard_reco_protodunehd_keepup.fcl $DATA -n 1