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per session/ job

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)


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  • 100GB for ECMWF staff
  • 10 GB for Member State users

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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


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  • 10 TB for ECMWF staff
  • 500 GB for Member State users


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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


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


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  • 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


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


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  • 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.

SSD on shared (GPIL) nodes 

(*f QoSs)

NVME 


Deleted at the end of session or job

Created

On ECS:

3 GB

per session/ job

by default.

  • Customisable up to 20 GB

  • On HPC:

    • 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

    RAM on exclusive parallel compute and GPU nodes

    (*p and *g QoSs)

    no limit (maximum memory of the node)

    LOCALSSD

    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.

    SSD on shared (GPIL) nodes for ecinteractive and JupyterHub sessions only.

    (ni QoS)

    GPU nodes are excluded


    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

    On ECS:

    • 3 GB per session/job by default.
    • Customisable up to 20 GB

    On HPC:

    3 GB per session/job by default.


  • Customisable up to 100 GB
  • Space and limits shared with TMPDIR

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    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, $TMPDIR and $LOCALSSD.

    $TEMP, which in the past was an alias to $SCRATCH, has been deprecated and is no longer defined. Please use $SCRATCH instead


    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.

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    Some special directories are not disk-based but actually mapped into the node's main memory. There are no limits set on exclusive nodes running on parallel queues. However, when running on shared nodes (GPILs) on fractional or interactive queues, this could lead to a single application or user exhausting all the memory of the node and thus impacting others. This is why the following limits are set:They are unique for every session, and are limited by the memory resources requested in the job.

    Directory
    /tmp
    /var/tmp
    /dev/shm
    DirectoryNew limit
    /tmp428 GB (80% of available memory) per user's session
    /var/tmp428 GB (80% of available memory) per user's session
    /dev/shm428 GB (80% of available memory) per user's session
    $XDG_RUNTIME_DIR64 MB per user's session

    Users should instead use the general purpose file systems available, and in particular, $TMPDIR or $SCRATCHDIR for temporary storage per session or job.

    Note
    titleAutomatic cleanup

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

    Special Filesystems

    See hereafter a list of the specialised filesystems on Atos:

    ...

    .

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    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.

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