Azure File Sync with ARC... Better together.
Hello Folks! Managing file servers across on-premises datacenters and cloud environments can be challenging for IT professionals. Azure File Sync (AFS) has been a game-changer by centralizing file shares in Azure while keeping your on-premises Windows servers in play. With AFS, a lightweight agent on a Windows file server keeps its files synced to an Azure file share, effectively turning the server into a cache for the cloud copy. This enables classic file server performance and compatibility, cloud tiering of cold data to save local storage costs, and capabilities like multi-site file access, backups, and disaster recovery using Azure’s infrastructure. Now, with the introduction of Azure Arc integration for Azure File Sync, it gets even better. Azure Arc, which allows you to project on-prem and multi-cloud servers into Azure for unified management, now offers an Azure File Sync agent extension that dramatically simplifies deployment and management of AFS on your hybrid servers. In this post, I’ll explain how this new integration works and how you can leverage it to streamline hybrid file server management, enable cloud tiering, and improve performance and cost efficiency. You can see the E2E 10-Minute Drill - Azure File sync with ARC, better together episode on YouTube below. Azure File Sync + Azure Arc: Better Together Azure File Sync has already enabled a hybrid cloud file system for many organizations. You install the AFS agent on a Windows Server (2016 or later) and register it with an Azure Storage Sync Service. From that point, the server’s designated folders continuously sync to an Azure file share. AFS’s hallmark feature is cloud tiering, older, infrequently used files can be transparently offloaded to Azure storage, while your active files stay on the local server cache. Users and applications continue to see all files in their usual paths; if someone opens a file that’s tiered, Azure File Sync pulls it down on-demand. This means IT pros can drastically reduce expensive on-premises storage usage without limiting users’ access to files. You also get multi-site synchronization (multiple servers in different locations can sync to the same Azure share), which is great for branch offices sharing data, and cloud backup/DR by virtue of having the data in Azure. In short, Azure File Sync transforms your traditional file server into a cloud-connected cache that combines the performance of local storage with the scalability and durability of Azure. Azure Arc comes into play to solve the management side of hybrid IT. Arc lets you project non-Azure machines (whether on-prem or even in other Clouds) into Azure and manage them alongside Azure VMs. An Arc-enabled server appears in the Azure portal and can have Extensions installed, which are components or agents that Azure can remotely deploy to the machine. Prior to now, installing or updating the Azure File Sync agent on a bunch of file servers meant handling each machine individually (via Remote Desktop, scripting, or System Center). This is where the Azure File Sync Agent Extension for Windows changes the game. Using the new Arc extension, deploying Azure File Sync is as easy as a few clicks. In the Azure Portal, if your Windows server is Arc-connected (i.e. the Azure Arc agent is installed and the server is registered in Azure), you can navigate to that server resource and simply Add the “Azure File Sync Agent for Windows” extension. The extension will automatically download and install the latest Azure File Sync agent (MSI) on the server. In other words, Azure Arc acts like a central deployment tool: you no longer need to manually log on or run separate install scripts on each server to set up or update AFS. If you have 10, 50, or 100 Arc-connected file servers, you can push Azure File Sync to all of them in a standardized way from Azure – a huge time saver for large environments. The extension also supports configuration options (like proxy settings or automatic update preferences) that you can set during deployment, ensuring the agent is installed with the right settings for your environment Note: The Azure File Sync Arc extension is currently Windows-only. Azure Arc supports Linux servers too, but the AFS agent (and thus this extension) works only on Windows Server 2016 or newer. So, you’ll need a Windows file server to take advantage of this feature (which is usually the case, since AFS relies on NTFS/Windows currently). Once the extension installs the agent, the remaining steps to fully enable sync are the same as a traditional Azure File Sync deployment: you register the server with your Storage Sync Service (if not done automatically) and then create a sync group linking a local folder (server endpoint) to an Azure file share (cloud endpoint). This can be done through the Azure portal, PowerShell, or CLI. The key point is that Azure Arc now handles the heavy lifting of agent deployment, and in the future, we may see even tighter integration where more of the configuration can be done centrally. For now, IT pros get a much simpler installation process – and once configured, all the hybrid benefits of Azure File Sync are in effect for your Arc-managed servers. Key Benefits for IT Pros: Azure File Sync + Azure Arc Centralized Management Azure Arc provides a single control plane in Azure to manage file services across multiple servers and locations. You can deploy updates or new agents at scale and monitor status from the cloud—reducing overhead and ensuring consistency. Simplified Deployment No manual installs. Azure Arc automates Azure File Sync setup by fetching and installing the agent remotely. Ideal for distributed environments, and easily integrated with automation tools like Azure CLI or PowerShell. Cost Optimization with Cloud Tiering Offload rarely accessed files to Azure storage to free local disk space and extend hardware life. Cache only hot data (10–20%) locally while leveraging Azure’s storage tiers for lower TCO. Improved Performance Cloud tiering keeps frequently used files local for LAN-speed access, reducing WAN latency. Active data stays on-site; inactive data moves to the cloud—delivering a smoother experience for distributed teams. Built-In Backup & DR Azure Files offers redundancy and point-in-time recovery via Azure Backup. If a server fails, you can quickly restore from Azure. Multi-site sync ensures continued access, supporting business continuity and cloud migration strategies. Getting Started with Azure File Sync via Arc Prepare Azure Arc and Servers Connect Windows file servers (Windows Server 2016+) to Azure Arc by installing the Connected Machine agent and onboarding them. Refer to Azure Arc documentation for setup. Deploy Azure File Sync Agent Extension Install the Azure File Sync agent extension on Arc-enabled servers using the Azure portal, PowerShell, or CLI. Verify the Azure Storage Sync Agent is installed on the server. See Microsoft Learn for detailed steps. Complete Azure File Sync Setup In the Azure portal, create or open a Storage Sync Service. Register the server and create a Sync Group to link a local folder (Server Endpoint) with an Azure File Share (Cloud Endpoint). Configure cloud tiering and free space settings as needed. Test and Monitor Allow time for initial sync. Test file access (including tiered files) and monitor sync status in the Azure portal. Use Azure Monitor for health alerts. Explore Advanced Features Enable options like cloud change enumeration, NTFS ACL sync, and Azure Backup for file shares to enhance functionality. Resources and Next Steps For more info and step-by-step guidance, check out these resources: Microsoft Learn – Azure File Sync Agent Extension on Azure Arc: Official documentation on installing and managing the AFS agent via Azure Arc. Azure File Sync Documentation: Comprehensive docs for Azure File Sync, including deployment guides, best practices, and troubleshooting. Azure Arc Documentation: Learn how to connect servers to Azure Arc and manage extensions. This is useful if you’re new to Arc or need to meet prerequisites for using the AFS extension. You, as an IT Pro, can provide your organization with the benefits of cloud storage – scalability, reliability, pay-as-you-go economics – while retaining the performance and control of on-premises file servers. All of this can be achieved with minimal overhead, thanks to the new Arc-delivered agent deployment and the powerful features of Azure File Sync. Check it out if you have not done so before. I highly recommend exploring this integration to modernize your file services. Cheers! Pierre RomanAzure File Sync: A Practical, Tested Deployment Playbook for ITPros.
This post distills that 10‑minute drill into a step‑by‑step, battle‑tested playbook you can run in your own environment, complete with the “gotchas” that trip folks up, why they happen, and how to avoid them. But first... Why Use Azure File Sync? Hybrid File Services: Cloud Meets On-Prem Azure File Sync lets you centralize your organization’s file shares in Azure Files while keeping the flexibility, performance, and compatibility of your existing Windows file servers. You can keep a full copy of your data locally or use your Windows Server as a fast cache for your Azure file share. This means you get cloud scalability and resilience, but users still enjoy local performance and familiar protocols (SMB, NFS, FTPS). Cloud Tiering: Optimize Storage Costs With cloud tiering, your most frequently accessed files are cached locally, while less-used files are tiered to the cloud. You control how much disk space is used for caching, and tiered files can be recalled on-demand. This enables you to reduce on-prem storage costs without sacrificing user experience. Multi-Site Sync: Global Collaboration Azure File Sync is ideal for distributed organizations. You can provision local Windows Servers in each office, and changes made in one location automatically sync to all others. This simplifies file management and enables faster access for cloud-based apps and services. Business Continuity and Disaster Recovery Azure Files provides resilient, redundant storage, so your local server becomes a disposable cache. If a server fails, you simply add a new server to your Azure File Sync deployment, install the agent, and sync. Your file namespace is downloaded first, so users can get back to work quickly. You can also use warm standby servers or Windows Clustering for even faster recovery. Cloud-Side Backup Note: Azure File Sync is NOT a backup solution.... But, you ca reduce on-prem backup costs by taking centralized backups in the cloud using Azure Backup. Azure file shares have native snapshot capabilities, and Azure Backup can automate scheduling and retention. Restores to the cloud are automatically downloaded to your Windows Servers. Seamless Migration Azure File Sync enables seamless migration of on-prem file data to Azure Files. You can sync existing file servers with Azure Files in the background, moving data without disrupting users or changing access patterns. File structure and permissions remain intact, and apps continue to work as expected. Performance, Security, and Compatibility Recent improvements have boosted Azure File Sync’s performance (up to 200 items/sec), and it now supports Windows Server 2025 and integrates with Windows Admin Center for unified management. Managed identities and Active Directory-based authentication are supported for secure, keyless access. Real-World Use Cases Branch Office Consolidation: Multiple sites, each with its own file server, can be consolidated into a central Azure File Share while maintaining local performance. Business Continuity: Companies facing threats like natural disasters use Azure File Sync to improve server recovery times and ensure uninterrupted work. Collaboration: Organizations leverage Azure File Sync for fast, secure collaboration across locations, reducing latency and simplifying IT management. The Quick Troubleshooting TL;DR Insufficient permissions during cloud endpoint creation → “Role assignment creation failed.” You need Owner or the Azure File Sync Administrator built‑in role; Contributor isn’t enough because the workflow must create role assignments. Region mismatches → Your file share and Storage Sync Service must live in the same region as the deployment target. Wrong identity/account → If you’re signed into the wrong tenant or account mid‑portal (easy to do), the wizard fails when it tries to create the cloud endpoint. Switch to the account that actually has the required role and retry. Agent/version issues → An old agent on your Windows Server will cause registration or enumeration problems. Use the latest agent and consider auto‑upgrade to stay current. Networking & access keys → Ensure access keys are enabled on the storage account and required outbound URLs/ports are allowed. Operational expectations → Azure File Sync runs on a roughly 24‑hour change detection cycle by default; for DR drills or immediate needs, trigger change detection via PowerShell. And remember: File Sync is not a backup. Back up the storage account. End‑to‑End Deployment Playbook 1) Prerequisites (don’t skip these) Storage account supporting SMB 3.1.1 (and required authentication settings), with access keys enabled. Create your Azure file share in the same region as your File Sync deployment. Establish a clear naming convention Windows Server for the File Sync agent (example: Windows Server 2019) Identity & Access: Assign either Owner or Azure File Sync Administrator (a least‑privilege built‑in role designed specifically for this scenario). Contributor will let you get partway (storage account, Storage Sync Service) but will fail when creating the cloud endpoint because it can’t create role assignments. 2) Lay down the cloud side In the Azure portal, create the file share in your chosen storage account/region. Create a Storage Sync Service (ideally in a dedicated resource group), again ensuring the region is correct and supported for your needs. 3) Prep the server On your Windows Server, install the Azure File Sync agent (latest version). During setup, consider enabling auto‑upgrade; if the server is down during a scheduled upgrade, it catches up on the next boot, keeping you current with security and bug fixes. Register the server to your Storage Sync Service (select subscription, resource group, and service). If you have multiple subscriptions, the portal can occasionally hide one, PowerShell is an alternative path if needed. 4) Create the sync topology In the Storage Sync Service, create a Sync Group. This is the container for both cloud and server endpoints. Under normal conditions, the cloud endpoint is created automatically when you select the storage account + file share. If you hit “role assignment creation failed” here, verify your signed‑in account and role. Switching back to the account with the proper role resolves it; you can then recreate the cloud endpoint inside the existing Sync Group. Add a server endpoint: pick the registered server (it must show up in the drop‑down, if it doesn’t, registration isn’t complete) and the local path to sync. 5) Cloud tiering & initial sync behavior Cloud tiering keeps hot data locally and stubs colder data to conserve space. If you disable cloud tiering, you’ll maintain a full local copy of all files. If enabled, set the Volume Free Space Policy (how much free space to preserve on the volume) and review recall policy implications. Choose the initial sync mode, merge existing content or overwrite. 6) Ops, monitoring, and DR notes Change detection cadence is approximately 24 hours. For DR tests or urgent cutovers, run the change detection PowerShell command to accelerate discovery of changes. Backups: Azure File Sync is not a backup. Protect your storage account using your standard backup strategy. Networking: Allow required outbound ports/URLs; validate corporate proxies/firewalls. Monitoring: Turn on the logging and monitoring you need for telemetry and auditing. 7) Performance & cost planning Evaluate Provisioned v2 storage accounts to dial in IOPS/throughput to your business needs and gain better pricing predictability. It’s a smart time to decide this up front during a new deployment. 8) Identity options & least privilege You can also set up managed identities for File Sync to reduce reliance on user principals. If you do use user accounts, ensure they carry the Azure File Sync Administrator role or Owner. Keep the agent updated; it’s basic hygiene that prevents a surprising number of issues. 9) Quotas & capacity troubleshooting Hitting quota problems? Revisit your Volume Free Space Policy (cloud tiering) and recall policy. Sometimes the answer is simply adding a disk or increasing its size as data patterns evolve. Key Benefits for Infra Teams Hybrid file services without forklift: Keep your existing Windows file servers while centralizing data in Azure Files, adding elasticity and resiliency with minimal disruption . Right‑sized capacity on‑prem: Cloud tiering preserves local performance for hot data and trims cold data footprint to stretch on‑prem storage further. Operational predictability: Built‑in auto‑upgrade for the agent and a known change detection cycle, with the ability to force change detection for DR/failover testing. Least‑privilege by design: The Azure File Sync Administrator role gives just the rights needed to deploy/manage sync without over‑provisioning. Performance on your terms: Option to choose Provisioned v2 to meet IOPS/throughput targets and bring cost clarity. Available Resources What is Azure File Sync?: https://learn.microsoft.com/azure/storage/file-sync/file-sync-introduction Azure Files: More performance, more control, more value for your file data: https://azure.microsoft.com/blog/azure-files-more-performance-more-control-more-value-for-your-file-data/ Azure File Sync Deployment Guide: https://learn.microsoft.com/azure/storage/file-sync/file-sync-deployment-guide Troubleshooting documentation : https://learn.microsoft.com/troubleshoot/azure/azure-storage/files/file-sync/file-sync-troubleshoot Azure File Sync “copilot” troubleshooting experience: https://learn.microsoft.com/azure/copilot/improve-storage-accounts Next Steps (Run This in Your Lab) Verify roles: On the target subscription/resource group, grant Azure File Sync Administrator (or Owner) to your deployment identity. Confirm in Access control (IAM). Create the file share in the same region as your Storage Sync Service. Enable access keys on the storage account. Install the latest agent on your Windows Server; enable auto‑upgrade. Register the server to your Storage Sync Service. Create a Sync Group, then the cloud endpoint. If you see a role assignment error, re‑check your signed‑in account/role and retry. Add the server endpoint with the right path, decide on cloud tiering, set Volume Free Space Policy, and choose initial sync behavior (merge vs overwrite). Open required egress on your network devices, enable monitoring/logging, and plan backup for the storage account. Optionally evaluate Provisioned v2 for throughput/IOPS and predictable pricing before moving to production. If you’ve got a scenario that behaves differently in the field, I want to hear about it. Drop me a note with what you tried, what failed, and where in the flow it happened. Cheers! Pierre
