vSAN Storage Calculator

Calculate usable storage capacity for VMware vSAN environments

vSAN Configuration

When enabled, shows side-by-side comparison of both architectures

Minimum 3 nodes required for calculation (recommended for production)

Common sizes: 1000 (1TB), 2000 (2TB), 4000 (4TB)

Enter capacity (capacity-tier) disks per node. Cache devices are configured separately below.

When a preference is selected, the calculator will prefer that policy if supported for the cluster size.

1 cache device(s) per disk group

With 6 capacity disks per node:
Disk groups (assume 5 capacity disks/group): 2

ESA requires vSAN 7.0+

Baseline (no additional compression/deduplication)

Reserved slack to allow for overhead (typical 20-30%)

Space used by checksums/metadata

Fill in the form and click Calculate to see results

OSA (Original Storage Architecture)

  • • Simple mirroring and erasure coding approach
  • • RAID 1/5/6 equivalent protection
  • • Good for smaller deployments
  • • More straightforward failure domain handling

ESA (Express Storage Architecture)

  • • Advanced deduplication and compression
  • • Better storage efficiency with intelligent tiering
  • • Optimized for large-scale deployments
  • • Requires vSAN 7.0 or later