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Storage Overview

Effective data management is essential for maintaining high performance and productivity when working on the Perun HPC cluster. This guide provides an overview of the available storage systems, their intended use cases, and general recommendations for optimal usage.

Backup Policy

Backup is not guaranteed across all filesystems.

  • /home is backed up daily.
  • /projects is backed up only for active projects monthly.
  • /scratch and /work have no backup.

Users are responsible for ensuring that important data is stored in appropriate locations.

For detailed information about storage quotas, see the Storage Quotas guide.

Storage Systems

After logging into the Perun cluster, several storage locations are available. Each filesystem is designed for a specific part of the computational workflow.

Overview of Available Filesystems on Perun

Mountpoints Capacity

  • /home

    • Personal directory unique to each user.
    • Intended for scripts, configuration files, and smaller datasets.

  • /projects

    • Shared directory accessible to all project members.
    • Used for storing project-related data and results.
    • Includes quotas per project.

  • /scratch

    • High-performance parallel filesystem.
    • Designed for large datasets and I/O-intensive workloads.

  • /work

    • Local storage on compute nodes.
    • Provides the highest I/O performance.
    • Accessible only during an active job.

Where to Run Calculations?

Mountpoint Capacity Accessible From Performance (Write/Read)
/home/username 250 TB Login & Compute Nodes 3 GB/s & 6 GB/s
/projects/project_id 9.4 PB Login & Compute Nodes 120 GB/s & 170 GB/s
/scratch/project_id 1.1 PB Login & Compute Nodes 240 GB/s & 350 GB/s
/work/SLURM_JOB_ID 3.84–7.68 TB Compute Nodes up to ~5–7 GB/s

Choosing the Right Filesystem

The optimal filesystem depends on workload size, I/O patterns, and storage requirements. In general, /work provides the highest performance when the available local capacity is sufficient.

Where to Store Data?

Storage locations are categorized according to their intended purpose.

Path (Mountpoint) Quota Retention Protocol
/home/username/ 300–500 GB None NFS

Details

Personal home directory for each user. This location should be used primarily for scripts, configuration files, and smaller datasets.

The path can be verified using:

echo $HOME
Path (Mountpoint) Quota Retention Protocol
/projects/<project_id> Defined per project 6 months Parallel FS

Details

Shared directory accessible to all members of a project.

  • Intended for shared project data, intermediate results, and final outputs.
  • Backed up only for active projects.
  • May include dedicated database directories.
Path (Mountpoint) Quota Retention Protocol
/scratch/<project_id> Defined per project 6 months Parallel FS

Details

Temporary storage intended for computational workloads.

  • Designed for large datasets and high-throughput I/O.
  • No backup — data should be considered non-persistent.
  • Accessible from all compute nodes.
  • Suitable for database-oriented workloads.
Path (Mountpoint) Quota Retention Protocol
/work/$SLURM_JOB_ID Unlimited Deleted after job completion XFS

Details

Local node storage available only during the execution of a job.

  • Highest I/O performance available on the system.
  • Suitable for workloads fitting within node-local capacity.
  • Data is automatically removed after job completion.

Detailed quota information is available in the Storage Quotas guide.

Home

Mountpoint Per-User Limit Backup Total Capacity Performance Protocol
/home 300–500 GB Yes 250 TB 3/6 GB/s NFS

The /home directory is the default storage location after login and contains the personal directory for each user.

Projects

Mountpoint Per-User Limit Backup Total Capacity Performance Protocol
/projects Defined per project Active only 9.4 PB 120/170 GB/s Parallel FS

Each user is assigned one or more project IDs, which are required for accessing project-related storage and computational resources. You can find your project ID(s) using:

id

Project directories follow the structure:

/projects/<project_id>

Data Retention Policy

Data in /projects is preserved for 6 months after the project concludes.

Scratch

Mountpoint Per-User Limit Backup Total Capacity Performance Protocol
/scratch Defined per project No 1.1 PB 240/350 GB/s Parallel FS

The /scratch directory provides high-performance temporary storage for computational workloads.

Directory structure:

/scratch/<project_id>

Data Retention Policy

Data in /scratch is preserved for 6 months after the project concludes.

Work

Mountpoint Per-User Limit Backup Total Capacity Performance Protocol
/work None No 3.84–7.68 TB up to ~5–7 GB/s XFS

The /work directory provides node-local storage with the highest performance.

This storage is available only during an active job and is intended for I/O-intensive workloads.

Details

  • Data is automatically removed after job completion.
  • Recommended for temporary high-performance computations.
Created by: Andrej Sec