Work Directories
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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). |
Access
Each user’s work space can be accessed through
/tmp/work/$USER
The path /tmp/work/$USER is available on all NCCS HPC systems. On the NCCS Cray XT4 (jaguar), Cray XT5 (jaguarpf), Data Analysis Cluster (lens), and Development Cluster (smoky), the /tmp/work/$USER path points to the same shared lustre area. On the IBM Blue Gene/P (eugene) the link points to a local area within the system’s General Parallel File System (GPFS).
Each project is also provided a large temporary area in the center wide file system. The area can be accessed through:
/tmp/proj/
Backup
Unlike the home areas, the /tmp/work/$USER and /tmp/proj/
space is NOT backed up. Users are responsible for backing up data to the HPSS.
Purge
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.
Permissions
By default, each user’s /tmp/work/$USER directory permissions are set to 0700. Changes made directly to the directory’s permissions will be overwritten hourly. To request a permission change, please contact the NCCS User Assistance Center.
Each project directory’s permissions are set to 770 with root as the owner and the project’s group as the group.
Permissions within each user’s /tmp/work/$USER and /tmp/proj/
/tmp
Do NOT create files directly in the /tmp directory. /tmp/work/$USER is actually a symbolic link to a completely different file system (like /scratch/lustre/$USER). The /tmp file system itself is quite small, and when /tmp fills up, system problems result.
Filesystems
GPFS
The local /tmp/work area on the NCCS IBM Blue Gene/P (eugene) utilizes the General Parallel File System (GPFS).
Lustre
The center-wide Lustre file system, Spider, is the default work file system for jaguar, jaguarpf, lens, smoky, and the data transfer nodes.
