The CFEL resource in Maxwell are own by a subgroup of CFEL-DESY and usage of the resources (compute & storage) is usually restricted to that group. If in doubt get in touch with the CFEL DESY admins.
The CFEL resource in Maxwell consists of a few interactive login nodes, some batch resources in the cfel partition and substantial GPFS storage. The compute nodes vary about the CPU-type and availability of GPUs. Please have a look
at Maxwell Hardware page, and the limits and constraints applying.
To login in to CFEL part of the maxwell cluster you have different:
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!
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:
[@max-exfl ~]$ my-partitions Partition Access Allowed groups ---------------------------------------------------------------------------------------------------------------- all yes all <------- will be available if any of the resources below is "yes! cfel yes cfel-wgs-users <------- look for this one as an CFEL member cms no max-cms-uhh-users,max-cms-desy-users cms-desy no max-cms-desy-users cms-uhh no max-cms-uhh-users cssb no max-cssb-users epyc-eval no all exfel yes exfel-wgs-users exfel-spb no exfel-theory-users,school-users exfel-th no exfel-theory-users exfel-theory no exfel-theory-users exfel-wp72 no exfel-theory-users fspetra no max-fspetra-users grid no max-grid-users jhub no all maxwell yes maxwell-users,school-users <------- might be granted if you have suitable applications p06 no max-p06-users petra4 no p4_sim ps no max-ps2-users psx no max-psx2-users uke no max-uke-users upex no upex-users,school-users xfel-guest no max-xfel-guest-users,p4_sim xfel-op no max-xfel-op-users xfel-sim no max-xfel-sim-users
If it says "yes" for partition "cfel" you are ready to go. If so you will also see a "yes" at least for partition "all". If not: get in touch with CFEL DESY admins! Let's assume that you've got the cfel-resource. The cfel-resource also offers great additional opportunities for remote login. It entitles you to use the max-display nodes to connect to the maxwell cluster via your browser or the fastx-client.
Apart from that: 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:
[@max-cfel ~]$ sbatch --partition=cfel --time=12:00:00 --nodes=1 my-application Submitted batch job 1613895 # the job might already be running [@max-cfel ~]$ squeue -u $USER JOBID PARTITION NAME USER ST TIME NODES NODELIST(REASON) 1614464 cfel my-app user R 0:06 1 max-cfel004 # Status of the job R: running. PD: pending
This works for any application smart enough not to strictly require an X-environment, matlab, comsol, ansys, mathematica, idl and many others can be executed as batch jobs. To make it more convenient you can add the SLURM directives directly into the script:
[@max-cfel ~]$ cat my-application #!/bin/bash #SBATCH --partition=cfel #SBATCH --time=1-12:00:00 # request 1 day and 12 hours #SBATCH --mail-type=END,FAIL # send mail when the job has finished or failed #SBATCH --nodes=1 # number of nodes #SBATCH --output=%x-%N-%j.out # per default slurm writes output to slurm-<jobid>.out. There are a number of options to customize the job [...] # the actual 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 firstname.lastname@example.org, we'll try our best.
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:
# request one node for 8 hours: [@max-cfel ~]$ salloc --nodes=1 --time=08:00:00 --partition=all salloc: Pending job allocation 1618422 salloc: job 1618422 queued and waiting for resources salloc: job 1618422 has been allocated resources salloc: Granted job allocation 1618422 salloc: Waiting for resource configuration salloc: Nodes max-cfel005 are ready for job # now you got a node allocated. So you can ssh into the node [@max-cfel ~]$ ssh max-cfel005 [@max-cfel005 ~]$ # run your application! [@max-cfel005 ~]$ exit # this terminates the ssh session, it does NOT terminate the allocation logout Connection to max-cfel005 closed. [@max-exfl ~]$ exit exit salloc: Relinquishing job allocation 1618422 # now your allocation is finished. If in doubt use squeue -u $USER or sview to check for running sessions!
There are a few things to consider:
Being member of CFEL and maybe having access to the cfel partition doesn't need to be the end of the story. If you have parallelized applications suitable for the Maxwell cluster you can apply for the Maxwell resource like everyone else on campus. Please send a message to email@example.com briefly explaining your use case. Being also a user of the European XFEL you might also have access to the UPEX partition. You can easily distribute your job over the partitions:
[@max-fsc ~]$ cat my-application #!/bin/bash #SBATCH --partition=cfel,maxwell,upex,all #SBATCH --time=1-12:00:00 # request 1 day and 12 hours #SBATCH --mail-type=END,FAIL # send mail when the job has finished or failed #SBATCH --nodes=1 # number of nodes #SBATCH --output=%x-%N-%j.out # per default slurm writes output to slurm-<jobid>.out. There are a number of options to customize the job [...] # the actual script.
The partition will be selected from cfel OR maxwell OR upex OR all starting with the highest priority partition. So your job will run on the cfel 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.
[@max-display001 ~]$ sinfo -p cfel -o "%10P %.6D %8c %8L %12l %8m %30f %N" PARTITION NODES CPUS DEFAULTT TIMELIMIT MEMORY AVAIL_FEATURES NODELIST cfel 6 64 1:00:00 14-00:00:00 512000 INTEL,V3,E5-2698,512G max-cfel[003-008] cfel 6 32 1:00:00 14-00:00:00 256000 INTEL,V3,E5-2640,256G max-cfel[011-016] cfel 4 40 1:00:00 14-00:00:00 256000 INTEL,V4,E5-2640,256G max-cfel[017-020] cfel 4 32 1:00:00 14-00:00:00 256000 INTEL,V2,E5-2650,256G,GPU,K20X max-cfelg[003-006] [@max-display001 ~]$ sinfo -p cfel -o "%10P %.6D %10s" PARTITION NODES JOB_SIZE cfel 20 1-6