Login nodes

Important

Login nodes are not for computing

Login nodes are shared among many users and therefore must not be used to run computationally intensive tasks. Those should be submitted to the scheduler which will dispatch them on compute nodes.

Note

Do and Don’ts

  • Avoid running calculations (with large IOPS) on the home disk,

  • Always use the queueing system,

  • Login nodes are for editing files, transfering files and submitting jobs,

  • Login nodes should be used to build specific binaries,

  • Do not run calculations interactively on the login nodes,

  • Offenders process will be killed without warnings!

The key principle of a shared computing environment is that resources are shared among users and must be scheduled. It is mandatory to schedule work by submitting jobs to the scheduler on PSMN’s clusters. And since login nodes are shared resources, they must not be used to execute computing tasks.

Acceptable use of login nodes include:

  • file transfers and file manipulations (compression, decompression, etc),

  • script and configuration file editing,

  • binary building, compilation,

  • short binary tests with small input/output (~10mn CPU time),

  • lightweight workflow tests on small datasets (~10mn CPU time),

  • job submission and monitoring.

Tip

You can submit jobs from any login node to any partition. Login nodes are only segregated for build (CPU µarch) and scratch access.

Here is a list of login nodes :

Todo

current testing stage:
  • no partition, no build -> x5570comp[1-2],

  • E5 -> c82gluster1,

  • Lake -> c6420node171,

  • Cascade -> s92node01

Final expected state (prone to changes):

Partition

login/build nodes

IB scratch

None

x5570comp[1-2]

None

E5

e5-2667v4comp[1-2]

/scratch/E5

Lake

m6142comp[1-2], cl5218comp[1-2], cl6242comp[1-2], cl6226comp[1-2]

/scratch/Lake

Epyc

/scratch/Lake

Cascade

s92node[01-02]

/scratch/Cascade

To access /scratch/E5/, you have to login with either one of e5-2667v4comp1 or e5-2667v4comp2.