How to create 1G zeroed sparse file in windows?

Question

In linux:

$ dd if=/dev/null of=mysparse seek=1G count=0
$ du -b mysparse
549755813888    mysparse
$ du -B1 mysparse
0       mysparse

In windows I have been playing with fsutil but I can not get the size on disk to be smaller than the size in the file properties.

Answer 1

Type NUL > temp
FSUtil Sparse SetFlag temp
FSUtil Sparse SetRange temp 0 0x40000000
FSUtil File SetEOF temp 0x40000000

It Creates a New File, then Sets the Sparseness Flag for it, then Sets that specific Range to Sparse. The size is in bytes.

You can also refer to the documentation: https://learn.microsoft.com/en-us/windows-server/administration/windows-commands/fsutil-sparse

Answer 2

May be this will help you: "SparseChecker" - manages sparse files on Windows NTFS It allows to operate with files, not with individual blocks of files as "fsutil" does.

Answer 3

What @Mehrdad said is correct.

However, whatever you write to the file (even ranges of zero) would be considered data to the operating system (and thus space allocated) and only FSCTL_SET_ZERO_DATA() would allow non-space occupying zeros to be written.

fsutil sparse setflag [file]

would allow a file to be set as sparse file.