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Storage Overview

The BNL Analysis Facility provides multiple storage systems optimized for different use cases.

Account Setup

Storage spaces may not be automatically granted to new Belle II accounts. You may need to request them via SDCC RT or contact support to have storage policies updated.

Storage Types Comparison

Storage Type Capacity Backups Use Case Access
Scratch 100 GB ❌ No Temporary work, compilation Interactive nodes only
dCache 5 TB ✅ Yes Long-term storage, analysis results Interactive nodes + Grid
Grid Varies ✅ Yes Belle II data, official samples Grid tools (gb2)

Quick Reference

Path Locations

# Scratch space
/gpfs/mnt/atlasgpfs01/belle2/users/USERNAME

# dCache user space
/pnfs/sdcc.bnl.gov/users/USERNAME

Usage Guidelines

  • Use scratch for: Code development, compilation, temporary files
  • Use dCache for: Analysis results, important data, long-term storage
  • Avoid on dCache: Small files, frequent I/O operations

Storage Best Practices

File Organization

# Home, intended for small config files and scripts. Example structure:
~/
├── .ssh/           # SSH keys and config
├── .globus/        # PEM files for Grid access
└── .jupyter/       # Jupyter configuration

# Scratch space structure. Examples:
/gpfs/mnt/atlasgpfs01/belle2/users/USERNAME/
├── build/             # Compilation outputs
├── tmp/               # Temporary files
└── git_repo/         # Active development

# dCache structure
/pnfs/sdcc.bnl.gov/users/USERNAME/
├── results/           # Large analysis outputs
├── datasets/          # Important data files
└── backup/            # Archive copies

Performance Tips

  1. Copy before frequent I/O operations: Move files to scratch for interactive analysis
  2. Batch operations: Group file operations to reduce overhead
  3. Clean regularly: Remove temporary files from scratch space

  4. Monitor quotas: Check usage with df -h and quota -u

  5. For information and technical details, refer to About dCache.

Quota Management

Check Usage

# Check scratch space usage
df -h /gpfs/mnt/atlasgpfs01/belle2/users/$USER

# Check dCache usage
df -h /pnfs/sdcc.bnl.gov/users/$USER

# Check detailed quota information
quota -us $USER

Some useful cleanup Commands

# Find large files
find /gpfs/mnt/atlasgpfs01/belle2/users/$USER -size +1G -ls

# Find old temporary files
find /gpfs/mnt/atlasgpfs01/belle2/users/$USER -name "*.tmp" -mtime +7 -delete