Get-S2DCapacityWaterfall
Computes the 7-stage theoretical capacity waterfall from raw physical to final usable capacity.
Synopsis
Extracts inputs from the live cluster session (physical disks, pool, volumes) and computes the 7-stage waterfall model. The waterfall is entirely theoretical — it represents what the hardware can deliver, not what has been provisioned.
Stage deductions are applied in sequence:
| Stage | Description | Deduction |
|---|---|---|
| 1 | Raw Physical | Pool-member capacity-tier disk total |
| 2 | After Format | File system and partition overhead (~0.9%) |
| 3 | After Pool Overhead | S2D pool management overhead (~1%) |
| 4 | After Reserve | Rebuild reserve: min(NodeCount, 4) × one drive |
| 5 | After Infrastructure | Azure Local system volumes (UserStorage, SBEAgent, etc.) |
| 6 | After Resiliency | Resiliency factor deduction (÷ NumberOfDataCopies) |
| 7 | Usable Capacity | Final available capacity for workload volumes |
Requires an active session from Connect-S2DCluster.
This cmdlet takes no parameters.
Syntax
Get-S2DCapacityWaterfallOutputs
S2DCapacityWaterfall — contains the full waterfall model.
Key properties:
| Property | Description |
|---|---|
Stages | Array of S2DWaterfallStage objects (one per stage) |
UsableCapacity | Final Stage 7 usable capacity as S2DCapacity |
RawCapacity | Stage 1 raw capacity as S2DCapacity |
ResiliencyFactor | The NumberOfDataCopies used in Stage 6 |
NodeCount | Number of cluster nodes contributing to the model |
ReserveStatus | Adequate or Critical based on reserve vs pool free |
BlendedEfficiencyPercent | Usable / raw capacity efficiency percentage |
Each S2DWaterfallStage:
| Property | Description |
|---|---|
StageNumber | 1–7 |
StageName | Human-readable stage name |
Capacity | Cumulative capacity at this stage as S2DCapacity |
Deducted | Amount deducted from the previous stage as S2DCapacity |
Description | Explanation of the deduction |
Examples
Compute and display:
Connect-S2DCluster -ClusterName "tplabs-clus01" -Credential $cred
Get-S2DCapacityWaterfallShow the stage table:
Get-S2DCapacityWaterfall | Select-Object -ExpandProperty Stages | Format-Table StageNumber, StageName, Capacity, DeductedGet the usable capacity number:
$waterfall = Get-S2DCapacityWaterfall
"Usable: $($waterfall.UsableCapacity.Display)"Related
See Capacity Math for a detailed explanation of each stage formula, and Collectors / Capacity Waterfall for the full pipeline context.