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. This article will learn how to configure 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 provide 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 read.
• 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.

Note: 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 will 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.

Get disk status

Note: 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.

PS C:\> Get-Disk | Format-Table -AutoSize

Number Friendly Name       Serial Number                    HealthStatus OperationalStatus Total Size Partition Style
------ -------------       -------------                    ------------ ----------------- ---------- ---------------
0      VMware Virtual disk 6000c2905397f746b506a29e5ae7fe22 Healthy      Online                 60 GB GPT
1      VMware Virtual disk 6000c29f28ba1e1b6d4b418ee5eec5c2 Healthy      Offline               100 GB RAW

The (C:) drive shows as number 0. The 100GB disk that we want to configure shows as Number 1, and it’s offline.

Set disk online

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

PS C:\> Set-Disk -Number 1 -IsOffline $False

PS C:\> Get-Disk | Format-Table -AutoSize

Number Friendly Name       Serial Number                    HealthStatus OperationalStatus Total Size Partition Style
------ -------------       -------------                    ------------ ----------------- ---------- ---------------
0      VMware Virtual disk 6000c2905397f746b506a29e5ae7fe22 Healthy      Online                 60 GB GPT
1      VMware Virtual disk 6000c29f28ba1e1b6d4b418ee5eec5c2 Healthy      Online                100 GB RAW

The disk is Online.

Convert the disk to partition style GPT

The partition style of disk number 1 shows as RAW. Let’s initialize the partition as GPT (GUID partition table).

PS C:\> Get-Disk 1 | Initialize-Disk -PartitionStyle GPT

PS C:\> Get-Disk | Format-Table -AutoSize

Number Friendly Name       Serial Number                    HealthStatus OperationalStatus Total Size Partition Style
------ -------------       -------------                    ------------ ----------------- ---------- ---------------
0      VMware Virtual disk 6000c2905397f746b506a29e5ae7fe22 Healthy      Online                 60 GB GPT
1      VMware Virtual disk 6000c29f28ba1e1b6d4b418ee5eec5c2 Healthy      Online                100 GB GPT

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

In this example, the name of the new volume will be Volume1, and the ReFS integrity streams will be disabled.

PS C:\> Get-Disk 1 | New-Partition -UseMaximumSize -DriveLetter E | Format-Volume -FileSystem REFS -AllocationUnitSize 65536 -NewFileSystemLabel "Volume1" -SetIntegrityStreams $false

DriveLetter FileSystemLabel FileSystem DriveType HealthStatus OperationalStatus SizeRemaining     Size
----------- --------------- ---------- --------- ------------ ----------------- -------------     ----
E           Volume1         ReFS       Fixed     Healthy      OK                     98.88 GB 99.81 GB

If you get a popup to format the disk drive, click Cancel.

The ReFS volume is successfully configured.

Start Windows Explorer and go to This PC. The (E:) drive shows up.

Verify ReFS volume in Exchange 2013/2016/2019

It’s always important to verify that the ReFS volume is successfully created.

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.

PS C:\> Get-CimInstance -ClassName Win32_Volume | Select-Object Label, BlockSize | Format-Table -AutoSize

Label    BlockSize
-----    ---------
              4096
Volume1      65536
Recovery      4096

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.

PS C:\> Get-FileIntegrity E:\Test.txt

FileName    Enabled Enforced
--------    ------- --------
E:\Test.txt False   True

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 the below example, it will create 4 volumes.

Get-Disk 1 | Initialize-Disk -PartitionStyle GPT -PassThru | New-Partition -UseMaximumSize -DriveLetter E | Format-Volume -FileSystem REFS -AllocationUnitSize 65536 -NewFileSystemLabel "DB01 Data" -SetIntegrityStreams $false
Get-Disk 2 | Initialize-Disk -PartitionStyle GPT -PassThru | New-Partition -UseMaximumSize -DriveLetter F | Format-Volume -FileSystem REFS -AllocationUnitSize 65536 -NewFileSystemLabel "DB01 Logs" -SetIntegrityStreams $false
Get-Disk 3 | Initialize-Disk -PartitionStyle GPT -PassThru | New-Partition -UseMaximumSize -DriveLetter G | Format-Volume -FileSystem REFS -AllocationUnitSize 65536 -NewFileSystemLabel "DB02 Data" -SetIntegrityStreams $false
Get-Disk 4 | Initialize-Disk -PartitionStyle GPT -PassThru | New-Partition -UseMaximumSize -DriveLetter H | Format-Volume -FileSystem REFS -AllocationUnitSize 65536 -NewFileSystemLabel "DB02 Logs" -SetIntegrityStreams $false

That’s it!

Note: Suppose you need to add more than 26 drives, you will hit the maximum number of drive letters you can create. An excellent way is to Configure mount points for Exchange Server and mount unlimited volumes to Exchange Server.

Conclusion

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 Exchange database dismounts unexpectedly. Don’t forget to follow us and share this article.