Edit

Share via

refsutil compression

The refsutil compression command is used to query or set the compression parameters on a specified Resilient File System (ReFS) volume. You can check the current compression status, apply compression using different formats, or decompress a compressed volume.

Syntax

refsutil compression <drive> <[/q]> | <[/c] [/f <format>] [/e <engine>] [/cs <size>]>

Parameters

Parameters Description
<drive> Specifies the drive letter of the volume to be compressed in the format E:.
/q Queries the volume's current compression parameters.
/c Compresses the volume with the specified compression parameters.
/f <format> Specifies the compression format to use. Valid options include:

  • LZ4: A fast compression algorithm.
  • ZSTD: A compression algorithm that offers a good balance between compression ratio and speed.
  • NONE: Used to decompress a previously compressed volume. When using NONE, omit the engine and compression chunk size parameters.
    		•
    /e <engine> Defines the compression level to use, which varies by format:

  • LZ4: Levels 1, 3-12. The default is 1.
    Levels 3-12 use the LZ4HC algorithm, which provides higher compression ratios at the cost of slower compression speeds.
  • ZSTD: Levels 1-22. The default is 3.
    Higher levels provide better compression ratios but reduce compression speed and might require more memory (especially levels 20 and greater).

    Decompression speed remains consistent regardless of the chosen compression level.

    • Omitting the /e parameter or using the value 0 sets the default level for any given compression format.
    /cs <size> Specifies the compression chunk size in bytes. This value must be to the power of two (2^n), at least equal to the volume's cluster size, and no greater than 64MB. Larger chunk sizes can enhance compression ratios but might negatively impact read performance for smaller data amounts. Beyond 1MB, the benefits diminish significantly, so larger sizes aren't recommended.

    If omitted or set to 0, the volume's cluster size is used.

    Note

    For the /e parameter, the default compression values are subject to change.

    Examples

    To query the F: volume compression parameters, run the command:

    refsutil compression F: /q

    To compress the F: volume using the LZ4 format with level 12 compression and a chunk size of 524,288 bytes (512 KB), run the command:

    refsutil compression F: /c /f LZ4 /e 12 /cs 524288

    To compress the F: volume using the ZSTD format with level 15 compression and a chunk size of 131,072 bytes (128 KB), run the command:

    refsutil compression F: /c /f ZSTD /e 15 /cs 131072

    To compress the F: volume using the ZSTD format with default compression parameters, run the command:

    refsutil compression F: /c /f ZSTD

    To decompress the F: volume, run the command:

    refsutil compression F: /c /f NONE