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Permanent Filesystems

Hint

Do not use permanent filesystems as work directories:

  • Even temporary files are kept in the snapshots and in the backup tapes over a long time, senselessly filling the disks,
  • By the sheer number and volume of work files, they may keep the backup from working efficiently.
Filesystem Name Usable Directory Availability Type Quota
Home /home global Lustre per user: 50 GB
Projects /projects global NFS per project

Global /home Filesystem

Each user has 50 GiB in a /home directory independent of the granted capacity for the project. The home directory is mounted with read-write permissions on all nodes of the ZIH system.

Hints for the usage of the global home directory:

  • If you need distinct .bashrc files for each machine, you should create separate files for them, named .bashrc_<machine_name>

If a user exceeds her/his quota (total size OR total number of files) she/he cannot submit jobs into the batch system. Running jobs are not affected.

Note

We have no feasible way to get the contribution of a single user to a project's disk usage.

Some applications and frameworks are known to store cache or temporary data at places where quota applies. You can change the default places using environment variables. We suggest to put such data in /tmp or workspaces. We cannot list all applications that do this, but some known ones are

Application Environment variable
Singularity SINGULARITY_CACHEDIR
pip PIP_CACHE_DIR
Hugging Face HF_HOME and TRANSFORMERS_CACHE
Torch Extensions TORCH_EXTENSIONS_DIR

Python virtual environments and conda directories can grow quickly, so they should also be placed inside workspaces.

Global /projects Filesystem

For project data, we have a global project directory, that allows better collaboration between the members of an HPC project. Typically, all members of the project have read/write access to that directory. It can only be written to on the login and export nodes.

Note

On compute nodes, /projects is mounted as read-only, because it must not be used as work directory and heavy I/O.

Backup

Just for the eventuality of a major filesystem crash, we keep tape-based backups of our permanent filesystems for 180 days. Please send a ticket to the HPC support team in case you need backuped data.

Quotas

The quotas of the permanent filesystem are meant to help users to keep only data that is necessary. Especially in HPC, it happens that millions of temporary files are created within hours. This is the main reason for performance degradation of the filesystem.

Note

If a quota is exceeded - project or home - (total size OR total number of files) job submission is forbidden. Running jobs are not affected.

The following commands can be used for monitoring:

  • show_resources shows your projects' usage of the filesystem.
  • quota -s -f /home shows the user's usage of the filesystem.

In case a quota is above its limits:

  • Remove core dumps and temporary data
  • Talk with your colleagues to identify unused or unnecessarily stored data
  • Check your workflow and use /tmp or the scratch filesystems for temporary files
  • Systematically handle your important data: