Workspaces/Advanced Features/Filesystems

Multiple Filesystem Locations

Most users don't need special filesystem options. On all clusters, workspaces are created on the default high-performance filesystem without any options - this works for standard I/O workloads.

Do I Need the -F Option?

For standard I/O (large files, sequential access):

• All clusters: Just use ws_allocate myWs 30 (no -F needed)
• The default filesystem handles standard workloads well

For special workloads (AI/ML, many small files, random I/O):

• NEMO2: Default Weka filesystem works great - no -F needed
• bwUniCluster 3.0: Use -F ffuc for flash filesystem
• Other clusters: Use $TMPDIR or default workspace

Check Available Filesystems

  $ ws_list -l                             # List available filesystems

If only one filesystem is listed, you're all set - just use ws_allocate without -F.

When -F Option is Available

Works on cluster	bwUC 3.0	BinAC2	Helix	JUSTUS 2	NEMO2
-F option	✓	✗	✗	✗	✗

Only bwUniCluster 3.0 offers multiple filesystems via -F option.

Cluster-Specific Information

NEMO2

Default Weka filesystem (no -F needed):

• Excellent for all workloads - standard I/O, small files, random access
• Handles AI/ML training, compilation, and general workloads efficiently
• Just use: ws_allocate myWs 30

bwUniCluster 3.0

Default Lustre filesystem (no -F needed):

• Best for standard I/O: large files, sequential access
• General-purpose workload
• Use: ws_allocate myWs 30

Flash filesystem with -F ffuc:

• SSD-based storage for special workloads
• Shared between bwUniCluster 3.0 and HoreKa (KIT/HoreKa users only)
• Use for: AI/ML datasets, many small files, random I/O, compilation
• Use: ws_allocate -F ffuc myWs 30

Other Clusters (BinAC2, Helix, JUSTUS 2)

• Single default filesystem (no -F option available)
• Good for all standard workloads
• For special workloads with many small files, consider using $TMPDIR

Simple Decision Guide

Your Workload	NEMO2	bwUniCluster 3.0
Standard I/O (large files)	ws_allocate myWs 30	ws_allocate myWs 30
AI/ML training	ws_allocate myWs 30	ws_allocate -F ffuc myWs 30
Many small files	ws_allocate myWs 30	ws_allocate -F ffuc myWs 30
Random I/O	ws_allocate myWs 30	ws_allocate -F ffuc myWs 30
Compilation/builds	ws_allocate myWs 30	ws_allocate -F ffuc myWs 30
Single-node temporary	Use $TMPDIR, not workspaces

Quick Reference by Data Type

Data Type	Where to Store
Large files, standard I/O	Default workspace (no -F) on all clusters
AI/ML datasets	NEMO2: default workspace; bwUniCluster 3.0: -F ffuc
Many small files	NEMO2: default workspace; bwUniCluster 3.0: -F ffuc
Random I/O patterns	NEMO2: default workspace; bwUniCluster 3.0: -F ffuc
Single-node temporary	Always $TMPDIR, not workspaces
Multi-node shared data	Default workspace on all clusters
Compilation/builds	NEMO2: default workspace; bwUniCluster 3.0: -F ffuc or $TMPDIR

For quota information, see Quotas & Limits.