The Maxwell cluster is composed of a Maxwell partition and resources which are contributed by various groups on the DESY campus.
The Maxwell partition is available for DESY members as well as external users of the Photon Science Facilities - under one condition: your application is suitable for high-performance computing. That could include
- multi-core MPI applications which can efficiently use most of the cores on a single or multiple nodes
- many-core applications requiring a very low-latency high-bandwidth network
- application with very high memory consumption
- photon science applications or simulations in need of GPU acceleration
Embarrassingly parallel applications like Monte-Carlo simulations are usually poor examples to utilize the resources effectively. We would advise to use the BIRD cluster instead.
If you think that the Maxwell cluster might help with your computational problems and your application is suited: just drop a message to firstname.lastname@example.org asking for the resource, but please explain very briefly what kind of applications you intend to run.
Please see: Maxwell for everyone for further information
If that's not the case you might still be entitled to use dedicated parts of the Maxwell cluster:
members of FS: see Maxwell for Photon Science members
External users of the PETRA3 and/or FLASH: see Maxwell for Photon Science users
Members of the European XFEL: see Maxwell for European XFEL
(External) users of the European XFEL: see Maxwell for European XFEL
Members of CFEL DESY: see Maxwell for CFEL
Members of the XFEL operating group: see Maxwell for XFEL
Members of CSSB: see Maxwell for CSSB
Group members for Petra4: see Maxwell for Petra4
- Members of CMS UHH or CMS DESY: see Maxwell for CMS
Your group is not among the ones listed? You still could contribute your resources to the Maxwell cluster for the benefit of everyone on campus. Check the "Bringing resources to maxwell" pages for options.
Very first step
You first want to verify which resources you can already use, or whom to contact in case your missing a resource. There are various ways to do that, depending on the account type available software (e.g. FastX).
What always works: open a terminal (e.g. putty), ssh to bastion.desy.de (desy-ps-ext.desy.de for external photon science users) and run a small scriplet called my-resources:
The HOME-Directory on Maxwell is /home/$USER. /home is mounted on a cluster file system (GPFS). More important:
/home has a single daily snapshot. It's not in backup and will not be archived. The snapshots are located in /home/.snapshot!
/home has a hard quota of 20GB!
Make sure to transfer important data to suitable resources (e.g. group specific storage).
Don't use it for any data crucial for your group! Once your account expires the data will be removed and will not be recoverable!
Storage and Scratch
Everyone with access to the Maxwell cluster also has access to BeeGFS storage space. To create your BeeGFS directory under /beegfs/desy/user/$USER just invoke the command mk-beegfs on one of the maxwell nodes. For more information on BeeGFS and other storage elements available please have a look at Storage on Maxwell.
Kerberos & AFS
Slurm jobs will NOT support AFS token or a Kerberos ticket! It means jobs will not suffer from expiring tokens or tickets. It also means that you can't rely on their existence. If your jobs need access to AFS directories it might be favorable to set ACLs enabling token-free access - if possible.
We strongly recommend to self-subscribe to be informed about changes and downtimes even if you are using only group-specific resources. Self-subscriptions are moderated and might take a moment.
Acknowledging the Maxwell Cluster
If the Maxwell cluster was an important asset in your work resulting in a publication, we'd greatly appreciate your acknowledgment. There is currently no publication to refer to and feel free to formulate an acknowledgment in your favorite terms. An example could look like this: This research was supported in part through the European XFEL and DESY funded Maxwell computational resources operated at Deutsches Elektronen-Synchrotron (DESY), Hamburg, Germany. We would definitely like to here about the publication! Please send references to publications to us, either to Frank Schluenzen or simply to the email@example.com. Have a look at the list of contributed publications.