Comparing NTFS and ReFS



  • Windows has recently joined the Linux and BSD worlds in having a selection of enterprise filesystems to choose from when working on Windows servers. In addition to the traditional NTFS filesystem that we have had for decades, we now have ReFS.

    NTFS stands for the [Windows] NT File System. ReFS stands for the Resilient File System. ReFS originated with Windows Server 2012 and contains a subset of NTFS functionality. ReFS tackles much of the same ground as ZFS and BtrFS, and has similarly garnered the same, odd excitement from IT professionals around odd use cases and a desire to implement outside of practical use cases.

    ReFS was designed to address needs with Windows Servers around Storage Spaces, software RAID and Hyper-V and is not designed to replace NTFS as the primary general purpose file system. It is targeted almost exclusively at large, local Hyper-V storage for virtual disks and for large, low cost file servers using software RAID. Like ZFS and BtrFS, ReFS builds features and functionality from LVM and software RAID layers into the filesystem and results in similar confusion around benefits and caveats because of it.

    With only rare exceptions, NTFS should be the normal choice for Windows systems. According to extensive tests by Josh Odgers* NTFS is more performant than ReFS, contrary to most assumptions (this is mirrored by ZFS which under normal conditions is not as fast as the decades old UFS filesystem) and has more features. And concerns on other sources point to reliability issues with ReFS, even when used with Storage Spaces (the full LVM layer) exactly as it is intended to be used. ReFS having reliability issues on its own is bad enough, but because ReFS is intended to be so resilient it lacks necessary tools to deal with it when it fails making it riskier still.

    ReFS exists essentially solely for use with Storage Spaces in software RAID scenarios where ReFS works with SS to add checksoming and data integrity to the stack.

    Compared to NTFS, ReFS is not just slower and uses slightly more system resources but it also lacks quotas, filesystem encryption via EFS, compression and deduplication. NTFS is the better choice for nearly all use cases.

    References:

    https://en.wikipedia.org/wiki/ReFS
    http://www.joshodgers.com/2016/07/10/storage-performance-refs-vs-ntfs/
    http://windowsitpro.com/hyper-v/dont-use-refs-hyper-v
    https://social.technet.microsoft.com/Forums/windowsserver/en-US/8363b69d-1eb1-4dfe-ace0-1fb6e4bf9adc/refs-and-hyperv-vhd?forum=winserverhyperv



  • More recent follow up available here: https://mangolassi.it/topic/9853/comparing-ntfs-and-refs



  • Veeam just announced this week that they now consider ReFS to be ready for production use for the first time due to last week's WIndows Server patch that addressed some ReFS issues.



  • Veeam just announced this week that they now consider ReFS to be ready for production use for the first time due to last week's WIndows Server patch that addressed some ReFS issues.