# Choose a File Sync share-migration branch from the actual cloud-tiering state

> DSE recommends recording the observed tiering state, source region, target region, and registered-server relationships before choosing the migration procedure.

- Canonical URL: https://update.dsesecurity.com/updates/dse-20260917-146-choose-a-file-sync-share-migration-branch-from-the-actual-cloud-tiering-state/
- Publisher: Detection Systems & Engineering (DSE Security)
- Author: DSE Security Editorial Team
- Published: 2026-09-17T16:32:34+00:00
- Modified: 2026-09-17T16:42:36+00:00
- Last reviewed by DSE: 2026-09-17
- Resource type: Guide
- DSE priority: Information
- Topics: IT
- Reading time: 2 minutes

## What you need to know

DSE recommends recording the observed tiering state, source region, target region, and registered-server relationships before choosing the migration procedure.

## Potentially affected

This review applies to a planned migration between SMB Azure file shares that already participate in Azure File Sync, including moves between regions.

## DSE recommendation

DSE recommends recording the observed tiering state, source region, target region, and registered-server relationships before choosing the migration procedure.

## Article

## Source facts

Microsoft separates File Sync share migration into procedures for cloud tiering being off or on. With tiering on, the guide copies data inside Azure to avoid unnecessary recalls through the source and says cutover requires downtime. For the tiering-enabled procedure, a cross-region move requires a new File Sync server connected to the target share because the registered server belongs to one Storage Sync Service and that service must share the share’s region. [Microsoft Learn](https://learn.microsoft.com/en-us/azure/storage/file-sync/file-sync-share-to-share-migration)

## Applicability

This review applies to a planned migration between SMB Azure file shares that already participate in Azure File Sync, including moves between regions.

## DSE recommendation

DSE recommends recording the observed tiering state, source region, target region, and registered-server relationships before choosing the migration procedure. Ask the workload owner to approve the cutover window and identify who controls source writes. Build the plan from the branch that matches those observations, with explicit source, staging, and target roles. For the tiering-enabled cross-region branch, include the replacement server before copying data.

## Verification

Recheck tiering state and regional relationships before the migration window. Compare the selected procedure with the recorded topology, and validate representative destination files and synchronization health during the approved test. Keep data-copy progress separate from cutover completion and document any unresolved server-registration or target-share issue.

## Official references

- [Microsoft: Migrate files between file shares when using Azure File Sync | Microsoft Learn](https://learn.microsoft.com/en-us/azure/storage/file-sync/file-sync-share-to-share-migration)

## Primary reference

- Name: Migrate files between file shares when using Azure File Sync | Microsoft Learn
- Authority: Microsoft Learn
- URL: https://learn.microsoft.com/en-us/azure/storage/file-sync/file-sync-share-to-share-migration
- Source publication date: Not stated by the source

## Citation and use

Preferred citation: “Choose a File Sync share-migration branch from the actual cloud-tiering state,” DSE Security, https://update.dsesecurity.com/updates/dse-20260917-146-choose-a-file-sync-share-migration-branch-from-the-actual-cloud-tiering-state/
Publishing principles: https://update.dsesecurity.com/updates/dse-updates-editorial-methodology/
Usage and citation policy: https://update.dsesecurity.com/usage/
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