Wednesday, June 8, 2016

DAG and ReFS

Hi folks,

When you are working on planning/deploying Exchange 2016 there's now a new good practice which MS published in the Exchange 2016 Preferred Arcitecture about file system used by database volumes. Now database volumes should be formatted with ReFS.

In this article 2 important considerations are added. Firstly, we will need to disable integrity streams bit on the database volume. This should be done during volume configuration and format. Don't miss it, otherwise you will have to re-do all your storage and even mailbox databases in DAG. In Windows 2012 R2 it can be done by the followig sample command (of course disk numbers and volume can vary in your environment):

Get-Partition –Disknumber 5 –PartitionNumber 2 | Format-Volume -FileSystem REFS -NewFileSystemLabel Volume3 -SetIntegrityStreams $false

Secondly, you will need to configure your DAG to user ReFS by as the file system. We need this to ensure that spare volume when used by AutoReseed is formatted by ReFS, rather than NTFS.

By default, file system for DAG is configured to be NTFS:


To confiure your DAG with ReFS as file system you will need to run the follwing command:

Set-DatabaseAvailabilityGroup NameOfYourDAG -FileSystem ReFS


I hope it will be extremely helpful for your DAG planning and deployment.

Enjoy!