What's New in Azure Files and Azure File Sync

Here’s a concise summary of the "What's new in Azure Files and Azure File Sync" article, organized by year and highlighting major announcements and links to the original details.

Last updated: 12/23/2025

What's new — 2025

Managed identity support for SMB Azure file shares — public preview
- VMs (Windows and Linux) can use managed identities with Microsoft Entra ID to access SMB Azure file shares (identity-based auth, no credentials). Useful for Azure services and customer apps. Read the blog post: https://techcommunity.microsoft.com/blog/azurestorageblog/secure-seamless-access-using-managed-identities-with-azure-files-smb/4477565
2025 Q3 — Azure Files vaulted backup for SSD file shares — Generally available
- Vaulted backup via Azure Backup protects SSD file shares (offsite, up to 10 years retention), manageable at scale via Azure Business Continuity Center; recommended to switch from snapshot backups.
2025 Q1 — Azure File Sync support for system-assigned managed identities — Generally available
- Eliminates need for shared keys by using system-assigned managed identities (Microsoft Entra ID). Learn more: https://docs.azure.cn/en-us/storage/file-sync/file-sync-managed-identities
2025 Q1 — Azure Files vaulted backup for HDD file shares — Generally available
- Vaulted backup support for HDD shares with same capabilities as for SSDs. More: https://docs.azure.cn/en-us/backup/azure-file-share-backup-overview?tabs=vault-standard
2025 Q1 — REST API support for NFS Azure file shares — public preview
- Data plane REST APIs for NFS shares enable tools/ISVs (AzCopy, Azure Backup, migration/DR scenarios) and include OAuth support (no storage account keys required).

What's new — 2024

Q4 — Azure File Sync support for system-assigned managed identities — public preview
- Managed identities for Storage Sync Service, registered server auth to Azure file share and to Storage Sync Service. Docs: https://docs.azure.cn/en-us/storage/file-sync/file-sync-managed-identities
Q4 — Azure File Sync v19 release
- Performance and security improvements, faster server provisioning, sync performance gains, preview managed identities support, and agent support for Windows Server 2025. Release notes: https://docs.azure.cn/en-us/storage/file-sync/file-sync-release-notes#version-19100
Q3 — Soft delete for NFS Azure file shares — Generally available
- Soft delete protection now available for NFS shares. Blog: https://techcommunity.microsoft.com/t5/azure-storage-blog/soft-delete-for-nfs-azure-file-shares-is-now-generally-available/ba-p/4162222
Q2 — Azure Files vaulted backup — public preview
- Preview of vaulted backups with scheduled policies and retention managed by Azure Backup.
Q1 — Large file share support for Geo/GeoZone redundancy — Generally available
- HDD file shares with GRS/GZRS can scale up to 100 TiB with improved IOPS/throughput. Info: https://docs.azure.cn/en-us/storage/files/files-redundancy#redundancy-in-a-secondary-region
Q1 — Snapshot support for NFS file shares — Generally available
- Share-level snapshot management for NFS via portal, REST, PowerShell, CLI. Learn more: https://docs.azure.cn/en-us/storage/files/storage-files-how-to-mount-nfs-shares#nfs-file-share-snapshots
Q1 — Sync upload performance improvements (Azure File Sync)
- Improvements targeted at initial uploads / high-churn scenarios.
Q1 — Expanded character support (Azure File Sync)
- Broader Unicode character support for SMB file/directory names; see unsupported-character guidance: https://learn.microsoft.com/troubleshoot/azure/azure-storage/file-sync-troubleshoot-sync-errors?toc=%2Fstorage%2Ffile-sync%2Ftoc.json&tabs=portal1%2Cazure-portal#handling-unsupported-characters
Q1 — New cloud tiering low disk space mode metric (Azure File Sync)
- New metric to alert when a server is in low disk space mode. Monitor: https://docs.azure.cn/en-us/storage/file-sync/file-sync-monitoring

What's new — 2023

Q4 — Azure Files supports all valid Unicode characters — GA
- Full Unicode support for SMB filenames; announcement: https://azure.microsoft.com/updates/azurefilessupportforunicodecharacters/
Q3 — Azure AD support for Azure Files REST API with OAuth — GA
- Identity-based REST access (share-level) for users/groups/managed identities. Blog: https://techcommunity.microsoft.com/t5/azure-storage-blog/public-preview-introducing-azure-ad-support-for-azure-files-smb/ba-p/3826733
Q2 — Scalability improvement for workloads that open root directory handles — GA
- Root directory handle limit increased from 2,000 to 10,000 per share (benefits AVD/FSLogix). Scale targets: https://docs.azure.cn/en-us/storage/files/storage-files-scale-targets
Q2 — Preview: large file share support for Geo/GZ redundancy (HDD)
- Preview improving capacity/performance for geo-redundant HDD file shares.
Q2 — New 99.99% SLA for SSD file shares
- 99.99% uptime per SSD file share (all protocols and redundancy types).
Q2 — REST API with OAuth — public preview
- Preview of identity-based REST access to file share data (same blog link as above).
Q2 — AD Kerberos authentication for Linux clients (SMB) — GA
- Kerberos for Linux clients using AD DS or Azure AD DS. Enable docs: https://docs.azure.cn/en-us/storage/files/storage-files-identity-auth-linux-kerberos-enable
Q1 — NFS nconnect for Azure file shares — GA
- Client-side Linux mount option to use multiple TCP connections (improves large-scale performance). Info: https://docs.azure.cn/en-us/storage/files/nfs-performance
Q1 — Improved Azure File Sync service availability
- Azure File Sync is zone-redundant (where availability zones are supported); recommended to use ZRS/GZRS for storage accounts. Redundancy info: https://docs.azure.cn/en-us/storage/files/files-redundancy

What's new — 2022

Q4 — Azure AD Kerberos auth for hybrid identities on Azure Files — GA (SMB)
- Hybrid identities (AD DS synced to Azure AD) can mount/access shares without on-prem AD connectivity. Enable guide: https://docs.azure.cn/en-us/storage/files/storage-files-identity-auth-hybrid-identities-enable
Q1 — Azure File Sync TCO improvements
- Reduced number of cloud transactions required for fully scanning shares, improving TCO and making cool tier more cost-effective for many customers.

What's new — 2021 (selected)

Q4 — Increased IOPS for SSD file shares
- Baseline IOPS increased (example: baseline formula changed from MIN(400 + 1GiB,100000) to MIN(3000 + 1GiB,100000)); burst floor increased (from 4,000 to 10,000). More: https://docs.azure.cn/en-us/storage/files/understanding-billing#provisioned-v1-model and https://azure.cn/pricing/details/storage/files/
Q4 — NFSv4.1 protocol support — GA (SSD)
- SSD shares support SMB or NFSv4.1 (POSIX-compliant). Info: https://docs.azure.cn/en-us/storage/files/files-nfs-protocol
Q4 — Symmetric throughput for SSD file shares
- Throughput provisioning can be used for full ingress, full egress, or mixed; formula updated. Details: https://docs.azure.cn/en-us/storage/files/understanding-billing#provisioned-v1-model
Q3 — SMB Multichannel — GA
- Multiple parallel SMB connections for higher throughput (SSD file shares, disabled by default). See: https://docs.azure.cn/en-us/storage/files/smb-performance
Q3 — SMB 3.1.1 and SMB security settings
- Added AES-128-GCM and AES-256-GCM encryption modes and configurable SMB security settings. Docs: https://docs.azure.cn/en-us/storage/files/files-smb-protocol#smb-security-settings
Q2 — Improved portal experience for domain joining to Active Directory
- Guided portal workflow for domain-joining storage accounts. Overview: https://docs.azure.cn/en-us/storage/files/storage-files-active-directory-overview