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Unit allocation size for a ReFS partition for Exchange 2019 RRS feed

  • Question

  • I know Microsoft generally recommends 4k when it comes to ReFS but for Exchange (2019) I was not able to find a clear (recent) answer: What is the recommended block size / cluster size for a partition that houses databases and transaction logs for Exchange 2019? 64k or 4k?
    Saturday, September 7, 2019 12:31 PM

All replies

  • Hi,

    According to the description in the official document: Resilient File System (ReFS) overview

    It mentions that:

    Variable cluster sizes - ReFS supports both 4K and 64K cluster sizes. 4K is the recommended cluster size for most deployments, but 64K clusters are appropriate for large, sequential IO workloads.

    For more detailed information: https://docs.microsoft.com/en-us/windows-server/storage/refs/refs-overview

    Regards,

    Joyce Shen


    Please remember to mark the replies as answers if they helped. If you have feedback for TechNet Subscriber Support, contact tnsf@microsoft.com.

    Monday, September 9, 2019 1:37 AM
  • Hi,

    Is there any update about your issue?

    Regards,

    Joyce Shen


    Please remember to mark the replies as answers if they helped. If you have feedback for TechNet Subscriber Support, contact tnsf@microsoft.com.

    Thursday, September 12, 2019 9:52 AM
  • I'm not as familiar with ReFS yet, but according to https://docs.microsoft.com/en-us/Exchange/plan-and-deploy/deployment-ref/storage-configuration?view=exchserver-2019 the NTFS allocation unit size best practice is 64K. I'm not sure why that would change between file system types.

    NTFS allocation unit size NTFS allocation unit size represents the smallest amount of disk space that can be allocated to hold a file. Supported: All allocation unit sizes.
    Best practice: 64 KB for both .edb and log file volumes.
    Supported: All allocation unit sizes.
    Best practice: 64 KB for both .edb and log file volumes.

    Thursday, September 12, 2019 4:14 PM
  • Hi,

    Do you have any further issue on this topic?

    Meanwhile, if there is no issue, please remember to mark helpful reply as answer to close the thread. Your action would be helpful to other users who encounter the same issue and read this thread.
    Thanks for your understanding.

    Regards,

    Joyce Shen


    Please remember to mark the replies as answers if they helped. If you have feedback for TechNet Subscriber Support, contact tnsf@microsoft.com.

    Thursday, September 19, 2019 5:32 AM