Every HPC node of both LiCCA and ALCC has access to the same network filesystem This filesystem contains the following folders, which currently share the same performance characteristics: Group home directory Backup All content of Pro Tip: All data that can easily be recreated (e.g. temporary files, python evironments, etc.) should be stored in the User scratch directory (not part of the Backup). Once Project and Cluster access have been approved, default permissions as well as user and group ownerships are applied to the four directories listed above. Permissions and ownerships of existing files and folders in these directories remain untouched. These directories can only be accessed by the owner and nobody else (except the root user). Default permissions of newly created files and folders are These directories can (only) be accessed and modified by all group members. Files and directories created by one member can be aribrarily modified or removed by any other group member. Note that user created files and folders in group directories won't have ACL an entry for special DO NOT attempt to "fix" file and folder permissions in group directories. Especially DO NOT run any kind of recursive Due to the nature of these ACL on group home and scratch directories, all files are marked as executable, and the output of DO NOT make your home or scratch folder world writable (e.g. To grant readonly access for your home and/or scratch directory to a specific group: The IdM group of choice should contain as few people as possible, because all members of this group will have read access to your personal home or scratch space this way. Recommendation: the respective To grant readonly access for your home and/or scratch directory to a specific user: You cannot modify the ACL of home and scratch group/project directories. To get access to another group's home or scratch folder you have to apply for Access to the Project Membership.Parallel File System (GPFS)
Overview
/hpc/gpfs2
which is a shared ressource./hpc/gpfs2/home/u/$USER
/hpc/gpfs2/scratch/u/$USER
/hpc/gpfs2/home/g/$HPC-Projekt/
/hpc/gpfs2/scratch/g/$HPC-Projekt/
/hpc/gpfs2/home
is backed up once a day to the Tape Library of the Rechenzentrum. All important data (e.g. results of calculations, user maintained software, etc.) is recommended to be stored in User home or Group directories.Default Permissions and Ownerships for User and Group directories
User directories
0644
and 0755
, respectively, due to the default umask setting of 0022
. This does not mean that other cluster user may access your files, because no regular user can get past your personal home and scratch directories, which act as gatekeepers.Group/Project directories
group
and other
(everyone) permissions, therefore the last two mode bits (e.g. 700) or corresponding output of ls -l
(e.g. -rwx------
) is completely meaningless.chmod
in group folders (e.g. chown -R
), even if you know what you are doing, because it is not necessary at all and will allocate useless extra metadata for every single file and folder.ls
may show all files with green color. Again, no need to fix this.Granting Access to User and Group directories
User directories
chmod 777
). This is explicitly forbidden and users doing so will receive a formal warning.rzhpc-*
group of your project.Group/Project directories