Storage Spaces Direct (S2D)Calculator for Azure Local
This planning tool helps determine the maximum supported individual volume size and the number of volumes needed based on storage pool utilization and resiliency for hyperconverged deployments of Azure Local and Windows Server.
Maximum supported individual volume size
3 copies | Thin provisioned | 4 machines | 1 GiB extents
The usable result includes 0.5 TB of volume overhead and remains below the 64 TB volume limit.
Storage Spaces Direct overview
Learn about the 64 TB volume limit
Four-copy resiliency has specific cluster topology requirements. View topology requirements
Tip: When using 3+ machines, having three copies of data is recommended for increased resiliency and performance.
Pool consumption
Estimate usable capacity and the number of maximum-size volumes required.
- Total pool capacity
- 204.8 TB
- Reserved for rebuild (4 x drives)
- 25.6 TB
- Available pool capacity
- 179.2 TB
- Usable capacity (with 3 copies)
- 59.7 TB
Note: Azure Local automatically reserves 256 GB for Infrastructure_1 and 20 GB for ClusterPerformanceHistory volumes from usable capacity.
4 servers x 8 drives (each) x 6.4 TB = 204.8 TB
Thin provisioningThin volumes use pool capacity
dynamically, as data is written,
but cannot exceed 20.8 TB each
Learn about the 4 PB pool limit
Enter a valid volume configuration to calculate pool consumption.
How the result is calculated
Understand how each volume's metadata database size and maximum record-count limit influence its usable capacity, based on the size of each record (extent).
- 01
Record capacity
4 MiB / 64 bytes / 2 = 32,768 records
- 02
Effective machine count
4 selected machines = 4 effective machines
- 03
Base record-limit formula
32,768 x 4 x 1 GiB / 6 = 21.33 TB
- 04
Usable volume size
21.33 TB - 0.5 TB overhead = 20.83 TB
Reference examples
Common base-limit configurations using 1 GiB extents.
| Provisioning | Extent | Machines | Copies | Maximum supported individual volume size |
|---|---|---|---|---|
| Thin | 1 GiB | 1 | 2 | < 15.5 TB Selected |
| Thin | 1 GiB | 2 | 2 | < 15.5 TB Selected |
| Thin | 1 GiB | 4 | 3 | < 20.8 TB Selected |
| Thin | 1 GiB | 6 | 3 | < 31.5 TB Selected |
| Thin | 1 GiB | 8 | 3 | < 42.1 TB Selected |
| Thin | 1 GiB | 4 | 4 | < 15.5 TB Selected |
| Fixed | 1 GiB | 2 | 2 | < 15.5 TB Selected |
| Fixed | 1 GiB | 4 | 3 | < 20.8 TB Selected |
| Fixed | 1 GiB | 6 | 3 | < 31.5 TB Selected |
| Fixed | 1 GiB | 8 | 3 | < 42.1 TB Selected |
| Fixed | 1 GiB | 4 | 4 | < 15.5 TB Selected |
| Fixed | 1 GiB | 6 | 4 | < 15.5 TB Selected |
| Fixed | 1 GiB | 8 | 4 | < 15.5 TB Selected |
| Fixed | 1 GiB | 16 | 2 | < 63.5 TB Selected |