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GPFS File Systems in the Jülich Environment

All user file systems on JUQUEEN/JUDGE are provided via GPFS from the fileserver JUST. The storage locations assigned to each user in the JUQUEEN/JUDGE environment are encapsulated with help of shell environment variables.

The following file systems are available ( Login Node or Compute Nodes, Front End Nodes (FENs) or I/O Nodes (IONs))

File SystemDescriptionTSM BackupJUDGE AccessJUQUEEN Access
$HOME

Full path to the users home directory inside GPFS

for source code, binaries, libraries, and applications

yesLogin + ComputeFENs + IONs
$WORK

Full path to the users standard scratch directory inside GPFS

temporary storage location for applications with large size and I/O demands;
data are automatically deleted (files after 90 days by modification and access date, empty directories after 3 days)

noLogin + ComputeFENs + IONs
$DATA

Full path to limited available users project data directory inside GPFS

storage for large projects in collaboration with JSC;
needed space must be applied for explicitly

yesLogin + ComputeFENs + IONs
$ARCH

Full path to users archive directory inside GPFS

storage for all files not in use for a longer time;
data are migrated to tape storage by TSM-HSM

yesLogin onlyFENs only
/usr/localsoftware repository (usage via $PATH, $LD_LIBRARY_PATH,...) yesLogin + ComputeFENs +IONs

All variables will be set during the login process by /etc/profile. It is highly recommended to access files always with the help of these variables.

Details about the different file systems can be found in
What file system to use for different data?

Details on naming conventions and access right rules for FZJ file systems are given in
HPC Data Rules for GPFS and Lustre File Systems.

File system resources will be controlled by quota policy for each group/project. For more information see
What data quotas do exist and how to list usage?

Good practice notes (use tar for lot of small files, don't rename directories)

  • Avoid a lot of small files
    Numerousness small files should be reorganized within tar-archives to avoid long access times due to deficiencies in file processing of the underlaying operating system.

  • Avoid renaming of directories
    Within all file systems that are backed up by TSM (except $WORK), a rename of directories within the data path should be done carefully because all data beyond the changed directory must be backed up once again. If a large amount of data is affected, it prevents backup of really new data in the entire file system and wastes system resources like CPU time, tape storage, and tape units.

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