Versions Compared

Key

  • This line was added.
  • This line was removed.
  • Formatting was changed.

...

Fast, local, non-critical data and files used in ecinteractive and JupyterHub sessions. Its contents are automatically archived when the session finishes so users can restore them on their next session and carry on where they left off. Can be used for development/compilation of projects interactively.

See AG: Local SSD storage for interactive sessions for more information on how to use this feature.

File System

Suitable for ...

TechnologyFeaturesQuota
HOMEpermanent files, e. g. profile, utilities, sources, libraries, etc. NFS

It is backed up.

Snapshots available. See AG: Recovering data from snapshots

Throttled I/O bandwidth from parallel compute nodes (less performance)


Show If
groupecmwf
  • 100GB for ECMWF staff
  • 10 GB for Member State users

Hide If
groupecmwf

10GB


PERMpermanent files without the need for automated backups, smaller input files for serial or small processing, etc.

NFS

No backup

Snapshots available.  See AG: Recovering data from snapshots

Throttled I/O bandwidth from parallel compute nodes (less performance)

DO NOT USE IN PARALLEL APPLICATIONS

DO NOT USE FOR JOB STANDARD OUTPUT/ERROR


Show If
groupecmwf
  • 10 TB for ECMWF staff
  • 500 GB for Member State users


Hide If
groupecmwf

500 GB


HPCPERMpermanent files without the need for automated backups,  bigger input files for parallel model runs, climate files, std output, etc.Lustre

No Backup

No snapshots

No automatic deletion


Show If
groupecmwf
  • 1 TB for ECMWF staff
  • 100 GB for Member State users without HPC access
  • 1 TB for Member State users with HPC access


Hide If
groupecmwf
  • 100 GB for users without HPC access
  • 1 TB for users with HPC access


SCRATCHall temporary (large) files. Main storage for your jobs and experiments input and output files.Lustre

Automatic deletion after 30 days of last access - implemented since 27 March 2023

No snapshots

No backup


Show If
groupecmwf
  • 50 TB for ECMWF staff and Member State users with HPC access
  • 2 TB for users without HPC access


Hide If
groupecmwf
  • 50 TB for users with HPC access
  • 2 TB for users without HPC access


SCRATCHDIR

Big temporary data for an individual session or job, not as fast as TMPDIR but higher capacity. Files accessible from all cluster.Lustre

Deleted at the end of session or job

Created per session/ job as a subdirectory in SCRATCH

part of SCRATCH quota

TMPDIR

Fast temporary data for an individual session or job, small files only. Local to every node.

NVME 


Deleted at the end of session or job

Created per session/ job


  • 3 GB per session/job by default.
  • Customisable up to 100 GB
  • Shared quota with LOCALSSD

To request more space in your jobs you can use the Slurm directive:

--gres=ssdtmp:<size>G

For ecinteractive and Jupyterhub sessions, space and limits are shared with LOCALSSD

LOCALSSD

NVME

Archived automatically at the end of session or job into $HPCPERM/.DO_NOT_DELETE_LOCALSSD_ARCHIVE

Recover manually on next session with:

ec_restore_local_ssd

Space and limits shared with TMPDIR



Tip
titleEnvironment variables

Those filesystems can be conveniently referenced from your session and scripts using the environment variables of the same name: $HOME, $PERM, $HPCPERM$SCRATCH, $SCRATCHDIR ,and $TMPDIR and $LOCALSSD.


Tip
titleMore capacity for $TMPDIR?

When running on the shared GPIL nodes (*f and *i QoSs), you may request a bigger space in the SSD-backed TMPDIR with the extra SBATCH option:

No Format
#SBATCH --gres=ssdtmp:<size>G

With <size> being a number up to 20 GB on ECS and 100 GB on HPCF. If that is still not enough for you, you may point your TMPDIR to SCRATCHDIR:

No Format
export TMPDIR=$SCRATCHDIR
Note that on interactive, non-gpu sessions using ecinteractive and Jupyterhub, the local space on disk is shared between TMPDIR and LOCALSSD.



Tip
titleHow much have I used?

You can check your current usage and limits with the "quota" command on hpc-login.

Filesystem structure

You will notice your filesystems have now a flat name structure. If you port any scripts or code that had paths to filesystems hardcoded from older platforms, please make sure you update them. Where possible, try and use the environment variables provided, which should work on both sides pointing to the right location in each case:

...

No Format
ssh hpc-login quota


Special directories on RAM

Some special directories are not disk-based but actually mapped into the node's main memory. They are unique for every session, and are limited by the memory resources requested in the job.

...

Note
titleAutomatic cleanup

Any data left on those spaces will be automatically deleted at the end of the job or session.

Show If
groupecmwf

Project Filesystems

Certain projects with special requirements have dedicated filesystems or volumes that are automatically mounted under /ec/vol/<project_name> on Atos GPIL shared nodes and VDI on first access. They are not available on Atos HPCF parallel compute nodes for performance reasons.

Those project volumes share the same backend as PERM, so the similar features apply:

  • NFS based,
  • No backups

The quota command will not show the limits for those filesystems. If you have any queries about them, please do raise an issue via our ECMWF Support Portal.