Can Azure File Shares Replace Your On-Premise File Server?

For decades, the on-premise file server has been the backbone of document storage for UK businesses. That humming box in the server cupboard — or the rack-mounted unit in the comms room — holds your company's files, folders, and shared drives. It is familiar, tangible, and has served you well. But it also comes with significant costs, risks, and limitations that many business owners have simply accepted as the price of doing business.

Azure File Shares, part of Microsoft's Azure cloud platform, offers a compelling alternative. It provides fully managed file shares in the cloud that are accessible via the standard SMB protocol — the same protocol your existing file server uses. This means your team can access Azure File Shares using the same mapped drives and file paths they are accustomed to, with no change to their daily workflow. The question is: can it genuinely replace your on-premise server?

This article provides an honest, detailed comparison to help UK SMEs make an informed decision about whether Azure File Shares is the right move for their business.

What Are Azure File Shares?

Azure File Shares is a fully managed cloud file storage service from Microsoft. It creates file shares that are accessible over the Server Message Block (SMB) protocol, which is the same protocol used by Windows file servers. This means users can connect to Azure File Shares using mapped network drives in exactly the same way they connect to a traditional file server.

The shares are hosted in Microsoft's UK data centres (UK South in London and UK West in Cardiff), ensuring your data remains within the United Kingdom for compliance and data sovereignty purposes. Microsoft manages all the underlying infrastructure — hardware, operating system, security patches, redundancy, and backups — so you never need to worry about server maintenance, hardware failures, or capacity planning.

Azure File Shares supports two performance tiers: Standard (backed by hard disk drives, suitable for general file sharing) and Premium (backed by solid-state drives, designed for latency-sensitive workloads). Most UK SMEs will find the Standard tier perfectly adequate for typical document storage and sharing needs.

On-Premise File Server vs Azure File Shares: A Direct Comparison

Consideration	On-Premise File Server	Azure File Shares
Upfront hardware cost	£5,000 – £15,000	£0
Monthly running cost	£100-300 (power, cooling, maintenance)	£50-200 (storage + transactions)
Hardware replacement	Every 5-7 years at full cost	Never — managed by Microsoft
Backup responsibility	Your responsibility to configure and test	Built-in snapshots + Azure Backup
Remote access	Requires VPN configuration	Native cloud access from anywhere
Disaster recovery	Requires separate DR plan and infrastructure	Geo-redundant storage across UK data centres
Security patching	Your responsibility to schedule and apply	Managed automatically by Microsoft
Scalability	Limited by hardware — upgrade means new server	Scale storage up or down as needed
Uptime SLA	No formal SLA — depends on your hardware	99.9% SLA guaranteed by Microsoft

The Cost Comparison: Real Numbers

Cost is often the deciding factor for UK SMEs considering a move to Azure File Shares. Let us examine realistic numbers for a typical small business with 1 TB of file storage.

An on-premise file server capable of holding 1 TB of usable storage (typically with RAID redundancy) costs between £5,000 and £10,000 for the hardware alone. Add the cost of Windows Server licensing (approximately £800 to £1,200), Client Access Licences (£30 to £40 per user), and annual maintenance and support, and the total five-year cost of ownership ranges from £10,000 to £20,000 — before accounting for the backup infrastructure needed to protect the data.

Azure File Shares Standard tier for 1 TB of storage costs approximately £35 to £50 per month, depending on redundancy options and transaction volumes. Over five years, that amounts to £2,100 to £3,000. Add Azure Backup at approximately £15 to £25 per month for the total to still come in well under the on-premise alternative. Even after accounting for the internet bandwidth costs of accessing cloud storage, Azure File Shares typically delivers significant savings — particularly when you factor in the elimination of hardware replacement cycles.

Five-year total cost comparison for 1 TB file storage (typical UK SME)

Azure File Sync: The Hybrid Approach

For businesses that are not ready to fully decommission their on-premise file server, Microsoft offers Azure File Sync — a hybrid solution that provides the best of both worlds. Azure File Sync keeps a local cache of your most frequently accessed files on your existing server while storing the complete file set in Azure File Shares.

This approach delivers several advantages. Users accessing files locally enjoy fast LAN-speed performance for frequently used files. Files that have not been accessed recently are stored only in Azure, freeing up local storage space. All files are backed up to the cloud automatically. And remote workers can access files directly from Azure without needing to VPN into the office.

Azure File Sync is particularly useful during the transition period. You can implement it alongside your existing file server, validate that everything works correctly, and then decommission the local server once you are confident in the cloud solution — or keep the hybrid setup permanently if it best suits your needs.

Migration: How to Move Your Files to Azure

Migrating from an on-premise file server to Azure File Shares is a well-documented process, but it requires careful planning to avoid data loss or disruption. The key steps include auditing your existing files, cleaning up unnecessary data, configuring the Azure File Share with appropriate permissions, performing the data transfer, and validating the results.

For the data transfer itself, Microsoft provides several tools. Azure File Sync can serve as both a migration tool and a long-term solution. Robocopy, a built-in Windows tool, can copy files with full permission preservation. For larger migrations, the Azure Data Box service allows you to ship a physical device to Microsoft for bulk data upload, avoiding the bandwidth limitations of internet-based transfer.

Plan the migration carefully. Test with a subset of data first. Validate permissions and access. Run a parallel operation period where both the old server and the new Azure share are available. And only decommission the on-premise server once you are fully confident in the new environment.

Security and Compliance Considerations

Data security is understandably a top concern for UK businesses considering cloud file storage. Azure File Shares provides enterprise-grade security that typically exceeds what most SMEs achieve with on-premise servers. Data is encrypted at rest using 256-bit AES encryption and in transit using SMB 3.0 encryption. Access is controlled through Azure Active Directory and NTFS-style permissions, providing the same granular access control you have on a Windows file server.

For UK GDPR compliance, Microsoft stores your data in UK data centres and provides comprehensive data processing agreements. Azure has achieved numerous compliance certifications including ISO 27001, SOC 2, and Cyber Essentials Plus. Microsoft's security team monitors the infrastructure continuously, applying patches and responding to threats far more rapidly than most SMEs could achieve on their own.