fsutil sparse

fsutil sparse

Applies to: Windows Server 2022, Windows Server 2019, Windows Server 2016, Windows 10, Windows Server 2012 R2, Windows 8.1, Windows Server 2012, Windows 8

Manages sparse files. A sparse file is a file with one or more regions of unallocated data in it.

A program sees these unallocated regions as containing bytes with a zero value and that there's no disk space representing these zeros. When a sparse file is read, allocated data is returned as stored, and unallocated data is returned, by default, as zeros, in accordance with the C2 security requirement specification. Sparse file support allows data to be deallocated from anywhere in the file.


fsutil sparse [queryflag] <filename>
fsutil sparse [queryrange] <filename>
fsutil sparse [setflag] <filename>
fsutil sparse [setrange] <filename> <beginningoffset> <length>


Parameter Description
queryflag Queries sparse.
queryrange Scans a file and searches for ranges that may contain nonzero data.
setflag Marks the indicated file as sparse.
setrange Fills a specified range of a file with zeros.
<filename> Specifies the full path to the file including the file name and extension, for example C:\documents\filename.txt.
<beginningoffset> Specifies the offset within the file to mark as sparse.
<length> Specifies the length of the region in the file to be marked as sparse (in bytes).



To mark a file named sample.txt in the c:\temp directory as sparse, type:

fsutil sparse setflag c:\temp\sample.txt

Additional References