Three times a week (Monday/Wednesday/Friday), John Savill tackles your most pressing IT questions.

Read through the FAQ archives, or send him your questions via email.

In this group of FAQs we dive into the brand new Azure Files Sync capability.

Q. What is Azure Files Sync?
Q. Can I use DFS-R on-premises between file servers and then Azure Files Sync to Azure Files?
Q. Any operational considerations when using Azure File Sync cloud tiering?

Q. What is Azure Files Sync?
Dept - Azure

A. Azure Files provides an SMB file service as part of an Azure Storage Account (along with BLOBs, tables and queues) that can be accessed via SMB 2.1 or 3. Azure Files Sync adds to this capability to enable Azure Files to be populated and replicated with on-premises Windows Server based file servers. Additionally multiple Windows Server based file servers can be connected to the same Azure Files Sync which will then all be kept synchronized via the Azure Files share. This means I could have 5 on-premises file servers replicated to a single Azure Files share via Azure Files Sync and the 5 on-premises file servers (along with the Azure Files share) will all synchronize with each other. You can also use Azure Backup to protect the Azure Files share to provide protection and point-in-time views of the data.

It can also use the Azure Files as a tier when the on-premises file server reaches a certain capacity threshold. Once the on-premises free space drops below a certain amount the least used data would be removed from the on-premises file server however a stub file is still shown and if accessed the data would be pulled down on-demand at a block level from the Azure Files share.

To use the synchronization a new Storage Sync Service instance is created, a new sync group created which consists of a single Azure Files share (the cloud endpoint) and then one or more server endpoints. For the server endpoints an agent is downloaded and installed on the Windows Server OS which is linked to the Storage Sync Service instance and allows it to be added to the sync group. The configuration is all done through the Azure portal.

Q. Can I use DFS-R on-premises between file servers and then Azure Files Sync to Azure Files?
Dept - Azure

A. No. You should never mix synchronization technologies, it can lead to many problems. Instead of using DFS-R between servers you would have all the servers synchronizing with each other via the Azure Files Sync thus using a single synchronization technology.

Q. Any operational considerations when using Azure File Sync cloud tiering?
Dept - Azure

A. When using the cloud tiering feature of Azure Files Sync the least used data is stored in Azure Files only while a stub remains on the regular file server. If a file that has been moved to the cloud tier (Azure Files) is accessed it is pulled back down and cached locally again. This means there are two key operational considerations.

  1. Don't try to perform full backups on-premises as the backup would access every block of every file and cause them all to be downloaded
  2. Be careful with anti virus scanning as once again if you try to perform a full scan it would access every block and again download every block of every file

Ideally perform the backups in Azure via Azure Backup of the Azure Files share and avoid doing full anti-virus scans and instead focus on scanning data as its written/accessed.