Storage Spaces & ReFS Resilient Volume Provisioning

Windows Server Storage Spaces can pool supported disks and provide mirror or parity resiliency. ReFS can detect file-data corruption when integrity streams are enabled; it can repair corruption only when a resilient mirror or parity space has a good alternate copy. These features do not replace a separate, tested backup. Integrity streams can also affect performance, so select the protected data and validate the workload.

Use dedicated disks and confirm the target before formatting

Creating a pool changes disk metadata, and formatting a volume erases its existing file system data. Use only disks dedicated to this pool, confirm their model, serial number, unique ID, and capacity, and verify a separate backup before continuing. Do not run the formatting step against a volume that contains data you need.

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Storage Spaces Resilience Profiles

Resilience Mode	Minimum Disks	Tolerance	Description & Recommendation
Simple (Stripe)	1	0 failures	High throughput, zero fault tolerance. Best for temp workloads.
Two-Way Mirror	2	1 disk failure	Writes two copies and can tolerate one disk failure. Confirm application and hardware support before using it for latency-sensitive workloads.
Three-Way Mirror	5	2 disk failures	Writes 3 copies of data. Maximum uptime for cluster shared volumes.
Parity	3	1 disk failure	High capacity efficiency. High compute overhead during random writes.

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Step 1: Discover Physical Disks and Create a Storage Pool

01

Discover Disks and Pool Storage

Storage Pool

Inspect unallocated physical disks capable of pooling and aggregate them into a centralized Storage Pool using PowerShell:

Inspect Raw Disks

# Inventory eligible disks. Confirm identity and capacity before selecting any.
Get-PhysicalDisk -CanPool $True |
  Select-Object FriendlyName, SerialNumber, UniqueId, DeviceId, MediaType,
    OperationalStatus, HealthStatus, Size, CannotPoolReason

Create Storage Pool

# Replace these examples with the UniqueId values of the dedicated disks
# you reviewed in the inventory tab. Do not select every eligible disk by default.
$SelectedUniqueIds = @(
  '<unique-id-of-first-dedicated-disk>'
  '<unique-id-of-second-dedicated-disk>'
)
$Candidates = Get-PhysicalDisk -CanPool $True
$Disks = @($Candidates | Where-Object { $SelectedUniqueIds -contains $_.UniqueId })
if ($Disks.Count -ne $SelectedUniqueIds.Count) {
  throw 'One or more selected disks were not found as eligible pool disks.'
}

$Disks | Format-Table FriendlyName, SerialNumber, UniqueId, Size
if ((Read-Host 'Type POOL only after confirming these dedicated disks') -cne 'POOL') {
  throw 'Pool creation cancelled.'
}

# Provision the storage pool using only the confirmed disks
New-StoragePool -FriendlyName "ProductionPool" `
  -StorageSubsystemFriendlyName "Windows Storage*" `
  -PhysicalDisks $Disks

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Step 2: Create a Mirrored Virtual Disk

02

Provision Resilient Virtual Disk

Virtual Disk

Create a two-way mirror and choose an explicit size that fits the pool’s usable mirrored capacity. Leave free capacity for future growth and repair operations. A mirror tolerates a disk failure within its layout; it does not protect against deletion, malware, or loss of the whole server.

Create 2-Way Mirror

# Set this to a size below the pool's usable mirrored capacity.
$VirtualDiskSize = 1TB

New-VirtualDisk -StoragePoolFriendlyName "ProductionPool" `
  -FriendlyName "DataMirror_VD" `
  -ResiliencySettingName "Mirror" `
  -NumberOfDataCopies 2 `
  -Size $VirtualDiskSize

Verify Virtual Disk

Get-VirtualDisk -FriendlyName "DataMirror_VD" | Select-Object FriendlyName, HealthStatus, OperationalStatus, Size

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Step 3: Format with ReFS & Enable Integrity Streams

03

Initialize, Format ReFS & Protect Data

ReFS Integrity

Initialize the new virtual disk with GPT, check that the example drive letter is unused, and format the new volume as ReFS. Formatting is destructive to the selected volume. Integrity streams are optional and can add I/O cost; enable them on data directories where the integrity benefit is appropriate.

Initialize and Format

# Confirm S: is not already assigned before using it.
if (Get-Volume -DriveLetter S -ErrorAction SilentlyContinue) {
    throw 'Drive letter S: is already in use. Choose an unused letter.'
}

# Initialize the newly created virtual disk and create a partition
$Disk = Get-VirtualDisk -FriendlyName "DataMirror_VD" | Get-Disk
$Disk | Initialize-Disk -PartitionStyle GPT -PassThru |
        New-Partition -DriveLetter "S" -UseMaximumSize

# Review the selected disk and partition, then explicitly confirm the format.
Get-Disk -Number $Disk.Number |
  Select-Object Number, FriendlyName, SerialNumber, UniqueId, OperationalStatus
Get-Partition -DriveLetter S |
  Select-Object DriveLetter, DiskNumber, Type, Size
if ((Read-Host 'Type FORMAT only after confirming this is the new empty volume') -cne 'FORMAT') {
    throw 'Volume formatting cancelled.'
}
Format-Volume -DriveLetter "S" -FileSystem ReFS -NewFileSystemLabel "EnterpriseData"

Enable Integrity Streams

# Enable integrity streams on the data directory. Child files inherit this setting.
New-Item -ItemType Directory -Path 'S:\Data' -Force
Set-FileIntegrity -FileName 'S:\Data' -Enable $True

# Verify the directory setting
Get-FileIntegrity -FileName 'S:\Data'

Figure 1: The two-way mirror is healthy, the S: volume is formatted as ReFS, and integrity streams are enabled.