File Systems

Notice:
Compute nodes can see only the Lustre work space.

The NFS-mounted home, project, and software directories are not accessible to the compute nodes.

  • Executables must be executed from within the Lustre work space.
  • Batch jobs can be submitted from the home or work space. If submitted from a user’s home area, the user should cd into the Lustre work space directory prior to running the executable through aprun. An error similar to the following may be returned if this is not done: 
            aprun: [NID 94]Exec /tmp/work/userid/a.out failed: chdir /autofs/na1_home/userid
        No such file or directory
  • Input must reside in the Lustre work space.
  • Output must also be sent to the Lustre file system.


Home Directories

Each user is provided a home directory to store frequently used items such as source code, binaries, and scripts. Please see the home directories page in the general support section for more details.


Project Directories

Each project is provided a directory to share project common files. Please see the project directories page in the general support section for more details.


Work Directories

Local work space is available on each NCCS high-performance computing (HPC) system for temporary files and for staging large files from and to the High Performance Storage System (HPSS). The space is not backed up. Additionally, to ensure adequate work space is available for user jobs, a script that finds and deletes old files runs on the system nightly. This script deletes files that have not been accessed or modified in more than 14 days. If the file system does not have sufficient free space after the script runs, then the script will run again with a threshold of fewer than 14 days. Thus, it is critical to archive files from the scratch area as soon as possible.

Each user’s work space can be accessed through

/tmp/work/$USER

The path /tmp/work/$USER is available on all NCCS HPC systems, but it points to a different file system on each supercomputer. Each one is local to that respective supercomputer.

Do not create files directly in the /tmp directory! /tmp/work/$USER is actually a symbolic link to a completely different file system (like /scratch/scr4tb/$USER). The /tmp file system itself is quite small, and when /tmp fills up, system problems result.

HPSS

The HPSS provides archival storage for NCCS users. Please see the HPSS section for more details.