Get-S2DVolumeMap

Maps all S2D volumes (virtual disks) with resiliency type, pool footprint, efficiency percentage, provisioning type, and infrastructure volume classification.

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Syntax

Get-S2DVolumeMap [[-VolumeName] <string[]>] [[-CimSession] <CimSession>]

Parameters

Parameter	Type	Description
-VolumeName	string[]	Limit results to specific volume friendly names.
-CimSession	CimSession	Override the module session CimSession.

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Output

Returns S2DVolume[] — one object per virtual disk.

Property	Type	Description
FriendlyName	string	Volume name
FileSystem	string	CSVFS_ReFS, CSVFS_NTFS, or Unknown
ResiliencySettingName	string	Mirror or Parity
NumberOfDataCopies	int	Data copy count (2 = two-way, 3 = three-way)
PhysicalDiskRedundancy	int	Disk failure tolerance
ProvisioningType	string	Fixed or Thin
Size	S2DCapacity	Logical volume size (what VMs see)
FootprintOnPool	S2DCapacity	Actual pool space consumed (includes resiliency overhead)
AllocatedSize	S2DCapacity	Bytes written to the volume (thin volumes only)
OperationalStatus	string	OK, InService, Online, or error state
HealthStatus	string	Healthy, Warning, or Unhealthy
IsDeduplicationEnabled	bool	Whether deduplication is active
IsInfrastructureVolume	bool	Azure Local infrastructure volume detection (see below)
EfficiencyPercent	double	Resiliency efficiency (logical ÷ footprint × 100)
OvercommitRatio	double	Thin overcommit ratio for this volume (AllocatedSize ÷ FootprintOnPool)
ThinGrowthHeadroom	S2DCapacity	Remaining write headroom before pool footprint equals provisioned size: Size − AllocatedSize. $null for fixed-provisioned volumes.
MaxPotentialFootprint	S2DCapacity	Maximum pool space this volume could consume if written completely full: Size × NumberOfDataCopies. $null for fixed-provisioned volumes.

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Resiliency Efficiency

EfficiencyPercent is computed per volume based on resiliency type and node count:

Configuration	EfficiencyPercent
Two-way mirror	50.0
Three-way mirror	33.3
Nested two-way mirror (2-node)	25.0
Single parity	66.7 (4-node) / 75.0 (6-node)
Dual parity (LRC)	50.0 (4-node) / 66.7 (6-node)

The blended efficiency across all workload volumes is reported as BlendedEfficiencyPercent on the S2DCapacityWaterfall object.

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Infrastructure Volume Detection

Azure Local automatically creates one or more infrastructure volumes for cluster metadata, storage bus layer logs, and CSV cache. Get-S2DVolumeMap detects these volumes and sets IsInfrastructureVolume = $true using two signals:

Name pattern match (any of):

• Infrastructure_<guid> — Azure Local infrastructure CSV
• ClusterPerformanceHistory — storage performance history
• Any name containing infra or infrastructure

Size heuristic:

• Volumes smaller than 600 GiB are flagged as infrastructure volumes

NOTE

Infrastructure volume in capacity math The infrastructure volume footprint is broken out in Stage 5 of the capacity waterfall so that it does not inflate the workload usable capacity figure. Use Where-Object IsInfrastructureVolume -eq $false to see workload volumes only.

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CIM Sources

Get-VirtualDisk

Volume objects are constructed from VirtualDisk WMI properties. File system type is inferred from the filesystem field; cluster shared volume association is implied by the CSV namespace path.

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Session Behavior

Results are cached in $Script:S2DSession.CollectedData['Volumes'] after first collection. Get-S2DCapacityWaterfall and Get-S2DHealthStatus read from this cache.

When -VolumeName is specified, the filter is applied after caching — all volumes are cached, but only the requested ones are returned to the caller.

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Examples

# All volumes with key properties
Get-S2DVolumeMap | Format-Table FriendlyName, ResiliencySettingName, Size, FootprintOnPool, EfficiencyPercent, IsInfrastructureVolume

# Workload volumes only
Get-S2DVolumeMap | Where-Object IsInfrastructureVolume -eq $false

# Thin-provisioned volumes with overcommit
Get-S2DVolumeMap | Where-Object ProvisioningType -eq 'Thin' | Format-Table FriendlyName, Size, AllocatedSize, OvercommitRatio

# Thin provisioning risk — max potential footprint vs current pool footprint
Get-S2DVolumeMap |
    Where-Object { $_.ProvisioningType -eq 'Thin' -and $_.MaxPotentialFootprint } |
    Format-Table FriendlyName, Size, ThinGrowthHeadroom, MaxPotentialFootprint, AllocatedSize

# Unhealthy volumes
Get-S2DVolumeMap | Where-Object HealthStatus -ne 'Healthy' | Format-List

# Single volume detail
Get-S2DVolumeMap -VolumeName "VM-Storage-01" | Format-List

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Troubleshooting

WARNING

No volumes returned If the command emits No virtual disks found, either no volumes have been created yet or the PSSession cannot see them. Verify on a cluster node:

Get-VirtualDisk | Format-Table FriendlyName, OperationalStatus, HealthStatus

!!! tip "Usable Capacity (Stage 7) is zero after Get-S2DCapacityWaterfall" If the final usable capacity is 0 TiB, no workload volumes were found — either all volumes are classified as infrastructure, or Get-S2DVolumeMap returned no results. Check:

```powershell
Get-S2DVolumeMap | Format-Table FriendlyName, IsInfrastructureVolume, Size
```

If all show `IsInfrastructureVolume = $true`, verify that workload CSV volumes have been created.