The National Institute for Computational Sciences

File Systems

File Systems

Beacon has access to three file systems: NFS, Lustre, and Local SSD.

NFS

NFS home directories have a 2 GB quota. The path to this directory is:

nics/[a-e]/home/$USER
This filesystem is only available on the login node and the compute nodes.

Lustre

Each user has a Lustre scratch directory in

/lustre/medusa/$USER
This filesystem is available to the login node, compute nodes, and all coprocessors.  There is no quota limit placed on Lustre; however, files older than 30 days are eligible to become purged: it is recommended to move your data once the calculation has completed. Any attempt to circumvent this purge policy may lead to deactivation of your account.

Local SSD

A root directory on the local SSD scratch space contains folders named mic0, mic1, etc., and is mounted by the compute nodes.  The coproccesors on the compute nodes mount their respective mic# folder.  These unique directories have an absolute path determined by the job id assigned by the scheduler, and can be accessed through the environment variable TMPDIR.

Visual representation of the Local SSD file system

Given the speed of the SSD drives, using $TMPDIR is preferable to using the Lustre scratch space.  The directories bin and lib are automatically created in each mic# folder for the user's convenience.  When a native mode application is finished running, all output should be copied out of $TMPDIR/mic# to either the NFS home or Lustre scratch file system.