The CSSB resources in Maxwell serve the CSSB members. Currently CSSB resources consist of the general CCSB nodes plus storage infrastructure, and the UKE partition for members of the Marlovits group. Below is the description for the CSSB partition, but rules apply to the UKE partition likewise.
For details about the setup of these partitions please have a look at the pages on hardware, limits and constraints .
Interactive Login Nodes
CSSB has its own display nodes. Preferably use these instead of the generic display nodes.
- ssh max-cssb-display.desy.de : will connect you to one of the CSSB display nodes. FastX might your better choice. Please have a look at the Remote Login and the FastX documentation. Currently max-cssb-display nodes are not accessible from outside the DESY network. Using them for remote login requires to tunnel through bastion.desy.de.
- ssh max-display.desy.de: will connect you to one of the display nodes. FastX might your better choice. Please have a look at the Remote Login and the FastX documentation.
- ssh max-wgs: will connect you to the generic login node.
- ssh max-cssba: is the interactive login node for UKE.
- Please note: max-display.desy.de is directly accessible from outside. All other login nodes can only be reached by first connecting to bastion.desy.de.
Login nodes are always shared resources sometimes used by a large number of concurrent users. Don't run compute or memory intense jobs on the login nodes, use a batch job instead!
The CSSB Batch resource in Maxwell
As a first step login to one of the login nodes and check which Maxwell resources are available for your account using the my-partitions command:
If it says "yes" for partition "cssb" you are ready to go. If so you will also see a "yes" at least for partition "all". If not: get in touch with it@cssb-hamburg.de. Let's assume that you've got the cssb-resource.
If you have an application, which is started by a script called my-application, and doesn't require a GUI, you can simply submit the script as a batch-job:
This works for any application smart enough not to strictly require an X-environment, matlab, comsol, ansys, mathematica, idl and many others can be executed as batch jobs. To make it more convenient you can add the SLURM directives directly into the script:
The email-notification will be sent to <user-id>@mail.desy.de. That should always work, so you don't actually need to specify an email-address. If you do, please make sure it's a valid address. For further examples and instructions please read Running Jobs on Maxwell.
If you think that it's much to complicated to write job-scripts or if you can't afford to invest the time to look into it: we are happy to assist. Please drop a message to maxwell.service@desy.de, we'll try our best.
Running interactive batch jobs
If you absolutely need an interactive environment, X-windows features like a GUI, there are options to do that in the batch environment. For example:
There are a few things to consider:
- Interactive jobs with salloc easily get forgotten, leaving precious resources idle. We do accounting and monitoring!
- Keep the time short: there is hardly a good reason to run an interactive jobs for more than the working hours. Use a batch job instead.
- Terminate allocations as soon as the job is done!
Other Maxwell Resources
Being member of CSSB and maybe having access to the uke partition doesn't need to be the end of the story. If you have parallelized applications suitable for the Maxwell cluster you can apply for the Maxwell resource like everyone else on campus. Please send a message to maxwell.service@desy.de briefly explaining your use case. You can easily distribute your job over the partitions:
The partition will be selected from cssb OR maxwell OR uke OR all starting with the highest priority partition. So your job will run on the cssb partition if nodes are available, on the maxwell partition if nodes are available and finally on the all partition if none of the other partitions specified have free nodes. Keep in mind that you should however select the partition according to the type of work you are doing. And a job can never combine nodes from different partitions, so check the limits applying to partitions.
To check availability of nodes and characteristics use sinfo (https://slurm.schedmd.com/sinfo.html)
[@max-wgs ~]$ sinfo -p cssb -o "%10P %.6D %8c %8L %12l %8m %30f %N" PARTITION NODES CPUS DEFAULTT TIMELIMIT MEMORY AVAIL_FEATURES NODELIST cssb 9 48 1:00:00 21-00:00:00 1500000 INTEL,Gold-6126,1536G max-cssb[002-010] cssb 3 40 1:00:00 21-00:00:00 512000 INTEL,V4,E5-2640,GPU,P100,GPUx max-cssbg[001-003] [@max-wgs ~]$ sinfo -p cssb -o "%10P %.6D %10s" PARTITION NODES JOB_SIZE cssb 12 1-8