How to View and Close Open Files in Windows Server SMB Share?

Windows file server administrators often have to force close the shared files that are open simultaneously by multiple users. This usually happens if the desktop software doesn’t work as expected, the user logs off incorrectly, or when the user opened a file and forgot to close it (went home, on vacation, etc.). In all these cases, the file on the shared network folder is still open (and locked) and cannot be modified by other users. Other users can see such a message when trying to open a locked file (depending on the application used): The document filename is locked for editing by another user. To open a read-only copy of his document, click…

In this article we’ll show you how to get the list of open files on a Windows file server, find out which user locked a file on a shared folder, and how to close (reset) file sessions to unlock open files.

View Open Files on a Shared Network Folder on Windows Server

You can get the list of files opened by users on Windows file server using the built-in Computer Management ( compmgmt.msc ) graphic snap-in.

Open the Computer Management console on your file server (or connect to the server remotely from the management console running on your computer) and go to System Tools -> Shared Folders -> Open files. A list of open files on current SMB server is displayed on the right side of the window. The list contains the local path to the file, the name of the user account that opens the file, the number of locks and the mode in which the file is opened (Read or Write+Read).

You can get the same list of open files using the built-in openfiles.exe console tool. For example, using the following command you can get the Session ID, username and full local path to the open file:

openfiles /Query /fo csv |more

You can display a list of open files on a remote server. For example, you need to list all open files in shared folders on the lon-fs01 host:

openfiles /Query /s lon-fs01 /fo csv

How to Find Out Who is Locking a File in a Shared Folder?

To identify the user who opened (locked) the filename.docx file on the shared network folder on the remote server lon-fs01, run this command:

openfiles /Query /s lon-fs01 /fo csv | find /i «filename.docx»

You can specify only a part of the file name. For example, you need to find out who opened an XLSX file containing “sale_report” in its name. Use the following pipe:

openfiles /Query /s lon-fs01 /fo csv | find /i «sale_report»| find /i «xlsx»

Of course you can find this file in the Computer Management GUI, but it’s less convenient (this console doesn’t provide search feature).

How to Forcibly Close an Open File on a SMB Share?

To close an open file, find it in the list of files in Open File section and select Close Open File in the context menu.

If there are hundreds of open files on your file server, it won’t be easy to find the specific file in the console. It is more convenient to use the Openfiles command line tool. As we have already told, it returns the session ID of the open file. Using this session ID you can force close the file by resetting the SMB connection.

First, you need to find the session ID of the open file:

openfiles /Query /s lon-fs01 /fo csv | find /i «farm»| find /i «.xlsx»

Disconnect the user from file using the received SMB session ID:

openfiles /Disconnect /s lon-fs01 /ID 617909089

You can forcefully reset all sessions and unlock all files opened by a specific user:

openfiles /disconnect /s lon-fs01/u corp\mjenny /id *

Get-SMBOpenFile: Find and Close Open File Handlers Using PowerShell

New cmdlets to manage shares and files on an SMB server appeared in PowerShell version for Windows Server 2012/Windows 8. These cmdlets can be used to remotely close network connections to an open file.

You can get a list of open files using the Get-SMBOpenFile cmdlet. Close-SmbOpenFile is used to close/reset the connection to a remote file.

To display a list of open files on the Windows SMB server, run the command:

The command returns the file ID, session ID and full file name(path).
You can display a list of open files with user and computer names (IP addresses):

You can list all files opened by a specific user:

Get-SMBOpenFile –ClientUserName «corp\mjenny»|select ClientComputerName,Path

or from a specific computer/server:

Get-SMBOpenFile –ClientComputerName 192.168.1.190| select ClientUserName,Path

You can display a list of open files by pattern. For example, to list all exe files opened from the shared folder:

or open files with a specific name:

The Close-SmbOpenFile cmdlet is used to close the open file handler. You can close the file by ID:

Close-SmbOpenFile -FileId 4123426323239

But it is usually more convenient to close the file by name:

Get-SmbOpenFile | where <$_.Path –like "*annual2020.xlsx">| Close-SmbOpenFile -Force

With the Out-GridView cmdlet, you can make a simple GUI form for finding and closing open files. The following script will list open files. You should use the built-in filters in the Out-GridView table to find open files for which you want to reset the SMB sessions. Then you need to select the required files and click OK. As a result, the selected files will be forcibly closed.

Get-SmbOpenFile|select ClientUserName,ClientComputerName,Path,SessionID| Out-GridView -PassThru –title “Select Open Files”|Close-SmbOpenFile -Confirm:$false -Verbose

How to Close Open Files on Remote Computer Using PowerShell?

The Get-SMBOpenFile and Close-SmbOpenFile cmdlets can be used to remotely find and close open (locked) files. First, you need to connect to a remote Windows SMB server via a CIM session:

$sessn = New-CIMSession –Computername lon-fs01

The following command will find the SMB session for the open file pubs.docx and close the file session.

Get-SMBOpenFile -CIMSession $sessn | where <$_.Path –like "*pubs.docx">| Close-SMBOpenFile -CIMSession $sessn

Confirm closing of the file by pressing Y . As a result, you have unlocked the file. Now other users can open it.

With PowerShell, you can close SMB sessions and unlock all files that a specific user has opened (a user went home and didn’t release the open files). For example, to reset all file sessions of the user mjenny, run this command:

Get-SMBOpenFile -CIMSession $sessn | where <$_.ClientUserName –like "*mjenny*">|Close-SMBOpenFile -CIMSession $sessn

How to view all network shares in Windows

Below are different methods of how a Microsoft Windows users may view their shares.

Access your computer on the network

To view visible shares in Windows, open the network path to your computer. For example, if your computer was named hope, you could view your computer by clicking Start, Run, and typing \\hope. Running this command opens a window and displays all available network shares. It is important to realize that this method does not show hidden shares. You need to use the net share command explained below to view hidden shares.

View your computer through «Network neighborhood» or «My Network Places»

Opening your computer through «Network neighborhood» or «My Network Places» allows you to view your computer’s shares and any other computer’s shares in your network.

«Network neighborhood» or «My Network Places» is accessible through the desktop. If you double-click one of these icons, and then double-click the workgroup belonging to your computer, you can view your computer’s shares.

Hidden shares are not displayed.

Use the MS-DOS «net share» command

Microsoft Windows users can use the «net share» command to view all shares (including the hidden shares) on a computer. To use this command, follow the steps below.

1. Click Start, Run, type cmd, and press Enter .
2. At the MS-DOS prompt, type net share and press Enter . Each of the shares, the location of the resource, and any remarks for that share are displayed. Below is an example of how this may look.

Deploy a file share witness

Applies to: Windows Server 2019, Windows Server 2016, Windows Server 2012 R2, Windows Server 2012

A file share witness is an SMB share that Failover Cluster uses as a vote in the cluster quorum. This topic provides an overview of the technology and the new functionality in Windows Server 2019, including using a USB drive connected to a router as a file share witness.

File share witnesses are handy in the following circumstances:

• A cloud witness can’t be used because not all servers in the cluster have a reliable Internet connection
• A disk witness can’t be used because there aren’t any shared drives to use for a disk witness. This could be a Storage Spaces Direct cluster, SQL Server Always On Availability Groups (AG), Exchange Database Availability Group (DAG), etc. None of these types of clusters use shared disks.

File share witness requirements

You can host a file share witness on a domain-joined Windows server, or if your cluster is running Windows Server 2019, any device that can host an SMB 2 or later file share.

File server type	Supported clusters
Any device w/an SMB 2 file share	Windows Server 2019
Domain-joined Windows Server	Windows Server 2008 and later

If the cluster is running Windows Server 2019, here are the requirements:

• An SMB file share on any device that uses the SMB 2 or later protocol, including:
  • Network-attached storage (NAS) devices
  • Windows computers joined to a workgroup
  • Routers with locally-connected USB storage
• A local account on the device for authenticating the cluster
• If you’re instead using Active Directory for authenticating the cluster with the file share, the Cluster Name Object (CNO) must have write permissions on the share, and the server must be in the same Active Directory forest as the cluster
• The file share has a minimum of 5 MB of free space

If the cluster is running Windows Server 2016 or earlier, here are the requirements:

• SMB file share on a Windows server joined to the same Active Directory forest as the cluster
• The Cluster Name Object (CNO) must have write permissions on the share
• The file share has a minimum of 5 MB of free space

• To use a file share witness hosted by devices other than a domain-joined Windows server, you currently must use the Set-ClusterQuorum -Credential PowerShell cmdlet to set the witness, as described later in this topic.
• For high availability, you can use a file share witness on a separate Failover Cluster
• The file share can be used by multiple clusters
• The use of a Distributed File System (DFS) share or replicated storage is not supported with any version of failover clustering. These can cause a split brain situation where clustered servers are running independently of each other and could cause data loss.

Creating a file share witness on a router with a USB device

At Microsoft Ignite 2018, DataOn Storage had a Storage Spaces Direct Cluster in their kiosk area. This cluster was connected to a NetGear Nighthawk X4S WiFi Router using the USB port as a file share witness similar to this.

The steps for creating a file share witness using a USB device on this particular router are listed below. Note that steps on other routers and NAS appliances will vary and should be accomplished using the vendor supplied directions.

Log into the router with the USB device plugged in.

From the list of options, select ReadySHARE which is where shares can be created.

For a file share witness, a basic share is all that is needed. Selecting the Edit button will pop up a dialog where the share can be created on the USB device.

Once selecting the Apply button, the share is created and can be seen in the list.

Once the share has been created, creating the file share witness for Cluster is done with PowerShell.

This displays a dialog box to enter the local account on the device.

These same similar steps can be done on other routers with USB capabilities, NAS devices, or other Windows devices.

Scale-Out File Server for application data overview

Applies to: Windows Server 2019, Windows Server 2016, Windows Server 2012 R2, Windows Server 2012

Scale-Out File Server is designed to provide scale-out file shares that are continuously available for file-based server application storage. Scale-out file shares provides the ability to share the same folder from multiple nodes of the same cluster. This scenario focuses on how to plan for and deploy Scale-Out File Server.

You can deploy and configure a clustered file server by using either of the following methods:

• Scale-Out File Server for application data This clustered file server feature was introduced in Windows Server 2012, and it lets you store server application data, such as Hyper-V virtual machine files, on file shares, and obtain a similar level of reliability, availability, manageability, and high performance that you would expect from a storage area network. All file shares are simultaneously online on all nodes. File shares associated with this type of clustered file server are called scale-out file shares. This is sometimes referred to as active-active. This is the recommended file server type when deploying either Hyper-V over Server Message Block (SMB) or Microsoft SQL Server over SMB.
• File Server for general use This is the continuation of the clustered file server that has been supported in Windows Server since the introduction of Failover Clustering. This type of clustered file server, and therefore all the shares associated with the clustered file server, is online on one node at a time. This is sometimes referred to as active-passive or dual-active. File shares associated with this type of clustered file server are called clustered file shares. This is the recommended file server type when deploying information worker scenarios.

Scenario description

With scale-out file shares, you can share the same folder from multiple nodes of a cluster. For instance, if you have a four-node file server cluster that is using Server Message Block (SMB) Scale-Out, a computer running Windows Server 2012 R2 or Windows Server 2012 can access file shares from any of the four nodes. This is achieved by leveraging new Windows Server Failover Clustering features and the capabilities of the Windows file server protocol, SMB 3.0. File server administrators can provide scale-out file shares and continuously available file services to server applications and respond to increased demands quickly by simply bringing more servers online. All of this can be done in a production environment, and it is completely transparent to the server application.

Key benefits provided by Scale-Out File Server in include:

• Active-Active file shares. All cluster nodes can accept and serve SMB client requests. By making the file share content accessible through all cluster nodes simultaneously, SMB 3.0 clusters and clients cooperate to provide transparent failover to alternative cluster nodes during planned maintenance and unplanned failures with service interruption.
• Increased bandwidth. The maximum share bandwidth is the total bandwidth of all file server cluster nodes. Unlike previous versions of Windows Server, the total bandwidth is no longer constrained to the bandwidth of a single cluster node; but rather, the capability of the backing storage system defines the constraints. You can increase the total bandwidth by adding nodes.
• CHKDSK with zero downtime. CHKDSK in Windows Server 2012 is significantly enhanced to dramatically shorten the time a file system is offline for repair. Clustered shared volumes (CSVs) take this one step further by eliminating the offline phase. A CSV File System (CSVFS) can use CHKDSK without impacting applications with open handles on the file system.
• Clustered Shared Volume cache. CSVs in Windows Server 2012 introduces support for a Read cache, which can significantly improve performance in certain scenarios, such as in Virtual Desktop Infrastructure (VDI).
• Simpler management. With Scale-Out File Server, you create the scale-out file servers, and then add the necessary CSVs and file shares. It is no longer necessary to create multiple clustered file servers, each with separate cluster disks, and then develop placement policies to ensure activity on each cluster node.
• Automatic rebalancing of Scale-Out File Server clients. In Windows Server 2012 R2, automatic rebalancing improves scalability and manageability for scale-out file servers. SMB client connections are tracked per file share (instead of per server), and clients are then redirected to the cluster node with the best access to the volume used by the file share. This improves efficiency by reducing redirection traffic between file server nodes. Clients are redirected following an initial connection and when cluster storage is reconfigured.

In this scenario

The following topics are available to help you deploy a Scale-Out File Server:

When to use Scale-Out File Server

You should not use Scale-Out File Server if your workload generates a high number of metadata operations, such as opening files, closing files, creating new files, or renaming existing files. A typical information worker would generate a lot of metadata operations. You should use a Scale-Out File Server if you are interested in the scalability and simplicity that it offers and if you only require technologies that are supported with Scale-Out File Server.

The following table lists the capabilities in SMB 3.0, the common Windows file systems, file server data management technologies, and common workloads. You can see whether the technology is supported with Scale-Out File Server, or if it requires a traditional clustered file server (also known as a file server for general use).

Technology Area	Feature	General Use File Server Cluster	Scale-Out File Server
SMB	SMB Continuous Availability (*)	Yes	Yes
SMB	SMB Multichannel	Yes	Yes
SMB	SMB Direct	Yes	Yes
SMB	SMB Encryption	Yes	Yes
SMB	SMB Transparent failover	Yes (if continuous availability is enabled)	Yes
File System	NTFS	Yes	NA
File System	Resilient File System (ReFS)	Recommended with Storage Spaces Direct	Recommended with Storage Spaces Direct
File System	Cluster Shared Volume File System (CSV)	NA	Yes
File Management	BranchCache	Yes	No
File Management	Data Deduplication (Windows Server 2012)	Yes	No
File Management	Data Deduplication (Windows Server 2012 R2)	Yes	Yes (VDI only)
File Management	DFS Namespace (DFSN) root server root	Yes	No
File Management	DFS Namespace (DFSN) folder target server	Yes	Yes
File Management	DFS Replication (DFSR)	Yes	No
File Management	File Server Resource Manager (Screens and Quotas)	Yes	No
File Management	File Classification Infrastructure	Yes	No
File Management	Dynamic Access Control (claim-based access, CAP)	Yes	No
File Management	Folder Redirection	Yes	Not recommended
File Management	Offline Files (client side caching)	Yes	Not recommended
File Management	Roaming User Profiles	Yes	Not recommended
File Management	Home Directories	Yes	Not recommended
File Management	Work Folders	Yes	No
NFS	NFS Server	Yes	No
Applications	Hyper-V	Not recommended	Yes
Applications	Microsoft SQL Server	Not recommended	Yes

Folder Redirection, Offline Files, Roaming User Profiles, or Home Directories generate a large number of writes that must be immediately written to disk (without buffering) when using continuously available file shares, reducing performance as compared to general purpose file shares. Continuously available file shares are also incompatible with File Server Resource Manager and PCs running Windows XP. Additionally, Offline Files might not transition to offline mode for 3-6 minutes after a user loses access to a share, which could frustrate users who aren’t yet using the Always Offline mode of Offline Files.

Practical applications

Scale-Out File Servers are ideal for server application storage. Some examples of server applications that can store their data on a scale-out file share are listed below:

• The Internet Information Services (IIS) Web server can store configuration and data for Web sites on a scale-out file share. For more information, see Shared Configuration.
• Hyper-V can store configuration and live virtual disks on a scale-out file share. For more information, see Deploy Hyper-V over SMB.
• SQL Server can store live database files on a scale-out file share. For more information, see Install SQL Server with SMB file share as a storage option.
• Virtual Machine Manager (VMM) can store a library share (which contains virtual machine templates and related files) on a scale-out file share. However, the library server itself can’t be a Scale-Out File Server—it must be on a stand-alone server or a failover cluster that doesn’t use the Scale-Out File Server cluster role.

If you use a scale-out file share as a library share, you can use only technologies that are compatible with Scale-Out File Server. For example, you can’t use DFS Replication to replicate a library share hosted on a scale-out file share. It’s also important that the scale-out file server have the latest software updates installed.

To use a scale-out file share as a library share, first add a library server (likely a virtual machine) with a local share or no shares at all. Then when you add a library share, choose a file share that’s hosted on a scale-out file server. This share should be VMM-managed and created exclusively for use by the library server. Also make sure to install the latest updates on the scale-out file server. For more information about adding VMM library servers and library shares, see Add profiles to the VMM library. For a list of currently available hotfixes for File and Storage Services, see Microsoft Knowledge Base article 2899011.

Some users, such as information workers, have workloads that have a greater impact on performance. For example, operations like opening and closing files, creating new files, and renaming existing files, when performed by multiple users, have an impact on performance. If a file share is enabled with continuous availability, it provides data integrity, but it also affects the overall performance. Continuous availability requires that data writes through to the disk to ensure integrity in the event of a failure of a cluster node in a Scale-Out File Server. Therefore, a user that copies several large files to a file server can expect significantly slower performance on continuously available file share.

Features included in this scenario

The following table lists the features that are part of this scenario and describes how they support it.