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Clearing Disks on Microsoft Storage Spaces Direct

This article provides instructions to clear out old storage pools, virtual disks and meta data left behind on hard drives on Storage Spaces Direct infrastructures.


When inserting disk drives into servers, and the disk was pulled from a server which had been configured with a Storage Spaces Storage Pool, the drive will have remnants of the prior Storage Pool.  When displaying existing storage pools, the storage pool from the prior server will show up as an “Unhealthy” storage pool and the disk will display as “not poolable”.  Disk drives will have any of several error states in the OperationalStatus or the HealthStatus.

The best practice when decommissioning a Storage Spaces system is to remove the Virtual Disks, then the Storage Pool.   This will release the disk drives and remove the Storage Pool metadata.  When removing single disks and leaving the Storage Pool intact, you will simply retire the disk.  This best practice is not always possible, especially in lab situations.   When trying to clear a disk with Storage Pool metadata, Storage Spaces will protect the old Storage Pool by preventing the disk from any operations such as initializing and formatting the disk.

When displaying the physical disks, you might see unhealthy disks such as this:


On the screenshot above, the physical disk list shows 48 disks on a server which only has 12 disks.   The server has been part of a 4 node Storage Spaces Direct cluster.  The server was reimaged without touching the 12 disks.   Storage Spaces Direct still has memory of the prior Storage Pool with 48 disks.

Sequence of Steps

Step 1 – Remove any Virtual Disks

Display any existing Virtual Disks.   Virtual Disks which are carried over from a different server will display with an error state.

List the existing Virtual Disks


Remove the Virtual Disk

Remove-VirtualDisk -FriendlyName <name>

Step 2 – Remove the Storage Pool

Remove StoragePool

List the physical disks.   The disks may be in a healthy state, or they may still be unusable.

Disk List with Unrecognized Metadata

Step 3 – Reset the Disks

Run a Physical Disk Reset to set the Operational Status of the disk.  This will remove the legacy pool information from the disks.

Run: Get-PhysicalDisk | ? OperationalStatus -eq "Unrecognized Metadata" | Reset-PhysicalDisk

Reset Physical Disks

Step 4 – Initialize Disks

If the OperationalStatus us Healthy the system is ready to use.

If there are disk drives are in an unknown state, the disks can now be initialized.

Commands to initialize disk to a raw state, set the disk to read/write, change the disk to online, then initialize the disk.

Get-PhysicalDisk –CanPool $false | Get-Disk | Set-Disk -isReadOnly $false

Get-PhysicalDisk –CanPool $false | Get-Disk | Set-Disk -isOffline $false

Get-PhysicalDisk –CanPool $false | Get-Disk | Clear-Disk -RemoveData -Confirm:$false

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1 Comment

  1. jesse Crowther

    Thanks for this post. Very helpful 🙂

    I was wondering if you knew how to overcome a permissiondenied error?
    We took down the lab domain and tried to format the S2D disks and found we couldn’t.



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