How to Check SMB Instance Type in Windows 11

Tuesday, October 13, 2026

How to Check SMB Instance Type in Windows 11

Learn how to check SMB instance types in Windows 11 using PowerShell and understand Default, CSV, SBL, and SR SMB instances.

Windows 11 includes PowerShell tools that can reveal detailed information about Server Message Block (SMB) shares and the infrastructure associated with them. One of the less commonly discussed properties is the SMB instance type, which can help administrators understand how a share is associated with a particular SMB workload or Windows storage infrastructure.

The Get-SmbShare cmdlet provides the -SmbInstance parameter for filtering SMB shares by instance type. Microsoft documents four accepted values: Default, CSV, SBL, and SR. These values are associated with normal SMB operations, Cluster Shared Volumes, Storage Spaces Direct, and Storage Replica scenarios respectively.

In this guide, you will learn how to check SMB instance types in Windows 11 using PowerShell, understand the four SMB instance values, filter shares by instance, inspect related properties, query remote computers, export the results, and troubleshoot unexpected SMB configurations.

What Is an SMB Instance?

An SMB instance identifies the type of SMB share instance associated with a particular storage or cluster workload. It provides additional context beyond the basic share name and local path.

For ordinary SMB file-sharing operations, the instance is generally associated with the Default SMB instance. Other instance values are designed for specialized Windows infrastructure scenarios.

The four documented values are:

Default — used for normal operations where a client opens a file on an SMB share on the server.
CSV — associated with Cluster Shared Volumes used by Windows Failover Clusters.
SBL — associated with Storage Spaces Direct.
SR — associated with Storage Replica.

Microsoft documents these values as the accepted values of the SmbInstance type used by Get-SmbShare.

Why Check SMB Instance Type?

Most home and small-office Windows 11 users will primarily encounter normal SMB shares. However, checking the SMB instance can be useful when troubleshooting advanced storage, virtualization, or cluster-related configurations.

You may want to check the SMB instance when:

Investigating an unusual SMB share.
Auditing SMB configuration on a Windows computer.
Troubleshooting clustered file-server infrastructure.
Investigating Cluster Shared Volume-related SMB activity.
Checking Storage Spaces Direct-related SMB resources.
Investigating Storage Replica configurations.
Comparing SMB share properties between computers.
Creating a detailed SMB configuration report.

The SMB instance should not normally be treated as an isolated troubleshooting property. It becomes more useful when viewed together with AvailabilityType, Scoped, ScopeName, ShareState, and ContinuouslyAvailable.

Open PowerShell in Windows 11

You can use Windows PowerShell or Windows Terminal to run the commands in this guide.

For a complete local SMB audit, open an elevated PowerShell session:

Press Windows + X.
Select Terminal (Admin) or PowerShell (Admin).
Approve the User Account Control prompt if Windows asks for permission.

Once PowerShell is open, you can begin by listing the SMB shares available on the computer.

How to List SMB Shares

Start with the standard Get-SmbShare command:

Get-SmbShare

Microsoft documents Get-SmbShare as the cmdlet used to retrieve objects representing SMB shares on the computer. The cmdlet includes parameters for properties such as share state, availability type, caching mode, leasing mode, scope, special status, and SMB instance.

A typical result can include columns such as:

Name       ScopeName Path             Description
----       --------- ----             -----------
ADMIN$     *         C:\Windows       Remote Admin
C$         *         C:\              Default share
Projects   *         D:\Projects      Project files

The standard table does not necessarily show every SMB property. To inspect the complete object, use Format-List *.

How to View the SMB Instance Property

You can use Select-Object to create a focused SMB inventory.

Get-SmbShare |
Select-Object Name, Path, SmbInstance

This command asks PowerShell to display the share name, local path, and SMB instance information.

Depending on the Windows version, SMB module version, and type of environment, the displayed properties can vary. If you need to see everything returned by the SMB share object, use:

Get-SmbShare |
Format-List *

This can reveal additional properties that are not displayed in the default table.

How to Check the Default SMB Instance

The Default instance represents normal SMB operations where a client opens files on an SMB share on the server.

You can filter shares associated with the default instance using:

Get-SmbShare -SmbInstance Default

You can also display only the properties that are useful for an audit:

Get-SmbShare -SmbInstance Default |
Select-Object Name, Path, SmbInstance, ShareState

For a typical Windows 11 computer used for ordinary file sharing, this is the most relevant SMB instance to understand.

How to Check the CSV SMB Instance

The CSV SMB instance is associated with Cluster Shared Volumes used by Windows Failover Clusters.

You can query it with:

Get-SmbShare -SmbInstance CSV

To display selected properties:

Get-SmbShare -SmbInstance CSV |
Select-Object Name, Path, SmbInstance, AvailabilityType, ContinuouslyAvailable

Do not expect ordinary standalone Windows 11 computers to return CSV shares. Cluster Shared Volumes are an advanced Windows clustering technology, so the presence of this instance is more relevant to specialized infrastructure than a normal desktop installation.

How to Check the SBL SMB Instance

The SBL SMB instance is associated with Storage Spaces Direct.

You can query it with:

Get-SmbShare -SmbInstance SBL

You can also display additional information:

Get-SmbShare -SmbInstance SBL |
Select-Object Name, Path, SmbInstance, AvailabilityType, ShareState

Storage Spaces Direct is an advanced Windows infrastructure technology, so this instance is primarily useful when investigating an environment that actually uses that technology.

How to Check the SR SMB Instance

The SR SMB instance is associated with Storage Replica.

To query shares associated with this instance:

Get-SmbShare -SmbInstance SR

You can display selected properties with:

Get-SmbShare -SmbInstance SR |
Select-Object Name, Path, SmbInstance, AvailabilityType, ShareState

As with CSV and SBL, most ordinary Windows 11 computers will not have a reason to expose SMB shares associated with this specialized infrastructure.

Compare All Four SMB Instance Types

The four documented values can be summarized as follows:

SMB Instance	Typical purpose	Environment
`Default`	Normal SMB file operations	Standard SMB file sharing
`CSV`	Cluster Shared Volumes	Windows Failover Cluster
`SBL`	Storage Spaces Direct	Advanced Windows storage infrastructure
`SR`	Storage Replica	Windows Storage Replica environments

Microsoft documents Default, CSV, SBL, and SR as the accepted values for the SmbInstance parameter.

How to Check Every SMB Instance in One Report

If you want a single inventory containing the SMB instance for every share, use:

Get-SmbShare |
Select-Object Name, Path, SmbInstance, ShareState, AvailabilityType

This gives you a useful overview of several related SMB properties.

You can also include scope and Continuous Availability:

Get-SmbShare |
Select-Object Name, Path, SmbInstance, ShareState, AvailabilityType, Scoped, ScopeName, ContinuouslyAvailable

This is particularly useful when investigating advanced SMB configurations because it puts several infrastructure-related properties next to each other.

SMB Instance vs Availability Type

SMB instance and availability type are related to advanced SMB environments, but they are not the same property.

SmbInstance identifies the SMB instance category, while AvailabilityType describes the availability configuration of the share.

You can display both:

Get-SmbShare |
Select-Object Name, Path, SmbInstance, AvailabilityType

For example, Microsoft documents availability types such as NonClustered, Clustered, ScaleOut, CSV, and DFS in the SMB share object model.

For a dedicated explanation of AvailabilityType, see How to Check SMB Share Availability Type in Windows 11.

SMB Instance vs ScopeName

ScopeName identifies the scope associated with an SMB share, particularly in advanced clustered file-server configurations.

It should not be confused with SmbInstance.

You can inspect both properties together:

Get-SmbShare |
Select-Object Name, Path, SmbInstance, Scoped, ScopeName

For more information about Scoped and ScopeName, see How to Check SMB Share Scope Name in Windows 11.

SMB Instance vs Special Shares

The Special property identifies special SMB shares such as administrative shares, default shares, and IPC$. This is different from the SMB instance type.

You can compare the properties:

Get-SmbShare |
Select-Object Name, Path, Special, SmbInstance

For example, an administrative share can be special without that fact alone telling you that it belongs to a specialized SMB instance.

For the dedicated guide, see How to Check Special SMB Shares in Windows 11.

Check SMB Instance and Share State

When troubleshooting an SMB resource, it can be useful to see the instance and current state together:

Get-SmbShare |
Select-Object Name, Path, SmbInstance, ShareState

The documented share states include Pending, Online, and Offline.

For a dedicated guide to this property, see How to Check SMB Share State in Windows 11.

Check SMB Instance and Continuous Availability

Advanced SMB environments may also use Continuous Availability. You can include the property in your inventory:

Get-SmbShare |
Select-Object Name, Path, SmbInstance, ContinuouslyAvailable

This is useful when investigating clustered or highly available file-server configurations.

For more information, see How to Check SMB Continuous Availability in Windows 11.

Check SMB Instance and Permissions

The SMB instance does not replace access-control information. If you find an unusual share, inspect its SMB share permissions separately.

Get-SmbShareAccess -Name "Projects"

You can also check a share that belongs to an advanced SMB environment when you know its name and scope.

For a detailed guide to SMB share permissions, see How to Check SMB Share Permissions in Windows 11.

Check SMB Instance and Active Sessions

If a share is currently being used, inspect active SMB sessions:

Get-SmbSession

This helps determine whether remote clients are actively connected to the SMB server.

See How to Check SMB Sessions in Windows 11 for a complete guide.

Check SMB Client Connections

Remember that SMB shares hosted by a computer and SMB connections made by the computer are different things.

To inspect client connections:

Get-SmbConnection

The SMB connection object also supports the -SmbInstance parameter, which means the same instance concept can be used when filtering certain SMB client connection information. Microsoft documents the accepted values as Default, CSV, SBL, and SR.

For more information, see How to Check SMB Connections in Windows 11.

How to Check a Specific SMB Instance

If you know which instance you want to investigate, use the -SmbInstance parameter directly.

For example:

Get-SmbShare -SmbInstance Default

Or:

Get-SmbShare -SmbInstance CSV

Or:

Get-SmbShare -SmbInstance SBL

Or:

Get-SmbShare -SmbInstance SR

If a particular instance is not present on the computer, the command may simply return no matching shares.

How to Build a Complete SMB Instance Inventory

For documentation purposes, you can combine the most useful share properties into one command:

Get-SmbShare |
Select-Object Name,
Path,
SmbInstance,
ShareState,
AvailabilityType,
Special,
Scoped,
ScopeName,
ContinuouslyAvailable,
CurrentUsers,
ConcurrentUserLimit

This creates a compact inventory covering both ordinary and advanced SMB configuration characteristics.

You can format the output as a table:

Get-SmbShare |
Select-Object Name, Path, SmbInstance, ShareState, AvailabilityType, Special, Scoped, ScopeName |
Format-Table -AutoSize

Export SMB Instance Information to CSV

If you are auditing multiple systems or keeping a record of the SMB configuration, export the results to a CSV file.

Get-SmbShare |
Select-Object Name, Path, SmbInstance, ShareState, AvailabilityType, Special, Scoped, ScopeName, ContinuouslyAvailable |
Export-Csv -Path "$env:USERPROFILE\Desktop\smb-instance-report.csv" -NoTypeInformation

The resulting file can be opened in a spreadsheet application and used as a configuration reference.

For a more complete report, include additional properties:

Get-SmbShare |
Select-Object Name, Path, Description, SmbInstance, ShareState, AvailabilityType, Special, Scoped, ScopeName, CachingMode, LeasingMode, EncryptData, CompressData |
Export-Csv -Path "$env:USERPROFILE\Desktop\smb-share-audit.csv" -NoTypeInformation

How to Check SMB Instance on a Remote Computer

You can use a CIM session to query SMB share information from a remote computer when remote management and permissions are correctly configured.

Create the CIM session:

$session = New-CimSession -ComputerName "PC01"

Then retrieve the SMB instance information:

Get-SmbShare -CimSession $session |
Select-Object Name, Path, SmbInstance, ShareState, AvailabilityType

When the investigation is complete, remove the CIM session:

Remove-CimSession $session

Microsoft documents -CimSession as an option for querying SMB shares on a remote computer.

Troubleshooting Unexpected SMB Instance Values

A Share Uses an Instance You Did Not Expect

Do not immediately assume that the configuration is incorrect.

First collect additional information:

Get-SmbShare -Name "ShareName" |
Format-List *

Pay particular attention to:

SmbInstance
AvailabilityType
Scoped
ScopeName
ShareState
ContinuouslyAvailable
Path
Special

These properties provide much more context than the instance value alone.

Default Is the Only Instance You See

This is normal for many ordinary Windows file-sharing environments.

The specialized values CSV, SBL, and SR are associated with specific Windows infrastructure technologies. A standalone Windows 11 computer does not need to expose shares using all four instance categories.

CSV Returns No Results

If this command returns no results:

Get-SmbShare -SmbInstance CSV

it does not necessarily indicate a problem. It may simply mean that the computer does not have SMB shares associated with a Cluster Shared Volume environment.

SBL or SR Returns No Results

The same principle applies to SBL and SR. These values are associated with specialized Windows storage infrastructure. A normal Windows 11 installation may have no matching SMB shares.

Do Not Change SMB Instance Values Without Understanding the Environment

The -SmbInstance parameter of Get-SmbShare is primarily an enumeration and filtering mechanism. It is not simply a switch that should be changed to optimize an ordinary SMB share.

If you discover an unexpected instance, first determine what Windows infrastructure created or uses the share.

Changing advanced SMB, cluster, or storage configuration without understanding the underlying architecture can cause service interruptions or unexpected behavior.

Useful PowerShell Commands

Command	Purpose
`Get-SmbShare`	List SMB shares
`Get-SmbShare -SmbInstance Default`	Filter normal SMB instance shares
`Get-SmbShare -SmbInstance CSV`	Check CSV SMB instance shares
`Get-SmbShare -SmbInstance SBL`	Check SBL SMB instance shares
`Get-SmbShare -SmbInstance SR`	Check SR SMB instance shares
`Get-SmbShare \| Select-Object Name,Path,SmbInstance`	Display SMB instance information
`Get-SmbShare -Name "Projects" \| Format-List *`	Display all properties of a share
`Get-SmbShareAccess -Name "Projects"`	Check share permissions
`Get-SmbSession`	Check active SMB sessions
`Get-SmbConnection`	Check SMB client connections

Frequently Asked Questions

What is SmbInstance in Windows 11?

SmbInstance identifies the SMB instance type associated with an SMB share or related SMB operation. Microsoft documents four values: Default, CSV, SBL, and SR.

How do I check the SMB instance?

Run:

Get-SmbShare |
Select-Object Name, Path, SmbInstance

What does the Default SMB instance mean?

Default is used for normal operations where an SMB client opens files on a share on the server.

What does CSV mean in SmbInstance?

CSV refers to the SMB instance used with Cluster Shared Volumes in Windows Failover Cluster environments.

What does SBL mean in SmbInstance?

SBL is associated with Storage Spaces Direct environments.

What does SR mean in SmbInstance?

SR is associated with Storage Replica environments.

Will a normal Windows 11 computer have CSV, SBL, and SR shares?

Usually, you should not expect a standard standalone Windows 11 computer to have shares for all of these specialized instance types. Their presence depends on the underlying Windows infrastructure.

Is SmbInstance the same as AvailabilityType?

No. SmbInstance identifies the SMB instance category, while AvailabilityType describes the share's availability configuration. They provide different information and can be inspected together.

Is SmbInstance the same as ScopeName?

No. ScopeName identifies the scope associated with an SMB share, while SmbInstance identifies the SMB instance category.

Final Thoughts

The SmbInstance property is a relatively advanced SMB configuration detail, but it can be valuable when troubleshooting Windows storage and clustered environments.

The simplest command for checking it is:

Get-SmbShare |
Select-Object Name, Path, SmbInstance

For filtering a particular instance, use the -SmbInstance parameter:

Get-SmbShare -SmbInstance Default

Microsoft documents four values: Default, CSV, SBL, and SR. The first is associated with normal SMB file operations, while the others are associated with specialized Windows infrastructure such as Cluster Shared Volumes, Storage Spaces Direct, and Storage Replica.

For ordinary Windows 11 file sharing, you may never need to change anything related to SMB instance types. However, knowing how to inspect the property can make SMB troubleshooting much more precise when a computer participates in advanced storage or cluster environments.

For the best results, always interpret SmbInstance together with other SMB properties such as share state, availability type, scope, Continuous Availability, permissions, sessions, and connections.

Related Windows 11 SMB guides: