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Configure ReFS volume Exchange 2013/2016/2019

Configure the ReFS volume before or after installing Exchange Server 2013/2016/2019. It’s important to configure the correct ReFS block size on the volume for Exchange. Before you start, run Windows Updates and reboot the system. In this article, you will learn how to configure the ReFS volume for Exchange Server 2013/2016/2019.

Support for ReFS Exchange Server 2013/2016/2019

  • ReFS is supported for volumes containing Exchange database files, log files, and content index files.
  • ReFS is not supported for volumes containing Exchange binaries (the program files).
  • ReFS is not supported for volumes containing the system partition.
  • ReFS integrity features are recommended to be disabled.

Disable ReFS integrity streams for performance

It’s good to know why it’s recommended to disable ReFS integrity features. Though integrity streams provides greater data integrity for the system, it also incurs a performance cost. There are a couple of different reasons for this:

  • If integrity streams are enabled, all write operations become allocate-on-write operations. Though this avoids any read-modify-write bottlenecks since ReFS doesn’t need to read or modify any existing data, file data frequently becomes fragmented, which delays reads.
  • Depending on the workload and underlying storage of the system, the computational cost of computing and validating the checksum can cause IO latency to increase.
Because integrity streams carry a performance cost, it’s recommended to leave integrity streams disabled on performance-sensitive systems.

Create ReFS volume in Exchange 2013/2016/2019

In the next steps, we are going to create a ReFS volume with PowerShell.

Important: Don’t use the New Volume Wizard when creating ReFS volumes. It does not give you the option to disable ReFS integrity streams at the volume level. To set it at the volume level itself use PowerShell when configuring new volumes.

Configure ReFS volume Exchange 2013 2016 2019 new volume wizard

Get disk status

It’s important to know how many volumes you need for the database and log files. This is different per Exchange Server design. Read the article Exchange database best practice before creating the ReFS volume

Get information regarding the disks in the system. Run the Get-Disk cmdlet.

The C:\ drive is showing as number 0. The 100GB disk that we want to configure is showing as Number 1 and it’s offline.

Configure ReFS volume Exchange 2013 2016 2019 disk unknown

Set disk online

Set the disk online and check the disk operational status. Run the Set-Disk cmdlet.

The disk is Online.

Convert the disk to partition style GPT

Partition style of disk number 1 is showing as RAW. Let’s initialize the partition as GPT (GUID partition table).

In Disk Management it will change the disk from Unknown/Not Initialized to Basic/Online.

Configure ReFS volume Exchange 2013 2016 2019 disk online

Mount the partition as drive letter E with the format volume ReFS and allocation unit size of 64K. We recommend configuring 64K allocation unit size/block size on the ReFS volume in Exchange. Read more in the following article. The name of the new volume will be Volume1 and the ReFS integrity streams will be disabled.

The ReFS volume is successfully configured

Configure ReFS volume Exchange 2013 2016 2019 disk configured

Start Windows Explorer and go to This PC. The E: drive is showing.

Configure ReFS volume Exchange 2013 2016 2019 disk configured in this pc

Verify ReFS volume in Exchange 2013/2016/2019

Verify ReFS allocation unit size/block size

Check and get the Allocation unit size. The block size will show as 65536. This means that it’s 64K.

Verify ReFS data integrity status

Create a test.txt file on the E:\ drive. Run the Get-FileIntegrity cmdlet. It will show that it’s not Enabled.

PowerShell one-liner creating ReFS volume

Create the ReFS volume with a PowerShell one-liner. This will save you some time if you have to configure more than one ReFS volume.


In this article, you learned how to configure ReFS volume in Exchange 2013/2016/2019. Create the ReFS volumes in Exchange before or after installing Exchange Server. Use PowerShell when creating ReFS volumes, otherwise you can’t disable ReFS integrity streams on the volume. Did you enjoy this article? You may also like Unable to install NuGet provider for PowerShell. Don’t forget to follow us and share this article.



ALI TAJRAN is a passionate IT Architect, IT Consultant, and Microsoft Certified Trainer. He started Information Technology at a very young age, and his goal is to teach and inspire others. Read more »

This Post Has 2 Comments

  1. Thank you for the great article, very interesting!

    And on that note… WHY, Microsoft, WHY? Time and time again you cannot do essential things with the standard tools, no, you have to fiddle around with power shell or other things! This is so frustrating! What is so difficult to put one or more check boxes into that create volume wizard?
    Why has some functionality to be hidden and to be accessed via another tool?
    You have great products, but the lenghts you create that someone has to go through…..
    Rant \end

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