Azure File Sync Agent v21.2 Release – July 2025

Improvements and issues that are fixed 

Azure File Sync Agent Now Available via Arc Extension

Windows servers connected through Azure arc can now install Azure File Sync agent using a new extension called, Azure File Sync Agent for Windows. The new extension is published by Microsoft and can be managed using the Azure Portal, PowerShell or Azure CLI. To learn more, see the Azure File Sync agent extension documentation.

Generally Available: Azure File Sync in Italy North 

The expansion into Italy North brings the service closer to organizations in these regions, offering lower latency, better performance, and support for local data residency requirements.  

Granular Role-Based Access Control (RBAC) for Azure File Sync 

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Azure File Sync now includes two dedicated built-in RBAC roles Azure File Sync Administrator and Azure File Sync Reader, designed to strengthen security and streamline operations for organizations managing file synchronization between on-premises and cloud environments. These roles offer more granular access control than broader roles like Owner or Contributor, enabling organizations to enforce the principle of least privilege more effectively.

Miscellaneous reliability and telemetry improvements for cloud tiering and sync​​​​​​​

Fixed an issue that caused sync download and cloud tiering failures with error code 0x80c80362 (ECS_E_ITEM_PATH_COMPONENT_HAS_ TRAILING_DOT) when a file or folder path included a trailing dot. Previously, users had to manually rename the affected item to resume sync. Azure File Sync now correctly handles path components with trailing dots, eliminating the need for manual intervention.

More information about the Azure File Sync Agent v21.2 release 

• This release is available for Windows Server 2016, Windows Server 2019, Windows Server 2022 and Windows Server 2025 installations. 

• The agent version for this release is 21.2.0.0. 

• The following updates must be installed on the Windows Server:

  • WS 2016 Microsoft Update Catalog (latest cumulative update)

  • WS 2019 Microsoft Update Catalog (latest cumulative update)

​​​​​​​Cumulative updates are released monthly. To deploy the latest one, users can use Windows Update or manually download it from the Microsoft Update Catalog. If installing manually, they should review the associated KB article to ensure all prerequisites are met.

​​​​​​​Note: If the Windows Updates are not installed prior to installing the Azure File Sync agent, the Storage Sync Agent service (FileSyncSvc) will fail to start. To learn more, see the Azure File Sync troubleshooting documentation. 

How to obtain and install the Azure File Sync Agent

 The Azure File Sync agent is available from Microsoft Update, Microsoft Update Catalog, and Microsoft Download Center. 

Notes 

• If the Azure File Sync agent is not currently installed on a server, use the agent installation package on the Microsoft Download Center. The agent installation package on Microsoft Update and Microsoft Update Catalog is intended for agent upgrades only.

• To update existing agent installations, run AfsUpdater.exe (located in the agent installation directory) or download and install the update from Microsoft Update or Microsoft Update Catalog.

Microsoft Update 

To obtain and install from Microsoft Update, follow these steps on a server that has Azure File Sync agent installed: 

1. Click Start, and then click Settings.

2. In Settings, click Update & security.

3. In the Windows Update window, click Check online for updates from Microsoft Update.

4. Verify the Azure File Sync agent update is listed and then click Install now.

Microsoft Update Catalog 

Go to the following website to manually download this update from the Microsoft Update Catalog: 

Azure File Sync Agent v21.2 release - July 2025 (KB5063825)

To manually install the update package, extract the cab file and run the following command from an elevated command prompt: 

msiexec.exe /p packagename.msp REINSTALLMODE=OMUS REINSTALL=StorageSyncAgent,StorageSyncAgentAzureFileSync,StorageSyncAgentGuardFilter,StorageSyncAgentUpdater /qb /l*v KB5063825.log 

For example, to install the Azure File Sync agent update for Server 2016, run the following command: 

msiexec.exe /p StorageSyncAgent_WS2016_KB5063825.msp REINSTALLMODE=OMUS REINSTALL=StorageSyncAgent,StorageSyncAgentAzureFileSync,StorageSyncAgentGuardFilter,StorageSyncAgentUpdater /qb /l*v KB5063825​​​​​​​.log 

Microsoft Download Center 

Go to the Microsoft Download Center​​​​​​​ to manually download the agent installation package for new agent installations. 

How to perform a silent installation for a new agent installation 

To perform a silent installation for a new agent installation that uses the default settings, run the following command at an elevated command prompt: 

msiexec /i packagename.msi /qb /l*v AFSv21.2Installation.log 

For example, to install the Azure File Sync agent for Windows Server 2016, run the following command: 

msiexec /i StorageSyncAgent_WS2016.msi /qb /l*v AFSv21.2Installation.log 

Notes 

Use the /qb switch to display restart prompts (if required), agent update, and server registration screens. To suppress the screens and automatically restart the server (if required), use the /qn switch.

To perform a silent installation with custom settings, see How to install the Azure File Sync agent silently.