We write a zeroed sector every 128 MiB, leaving other sectors untouched
This helps users visualize the progress of actual file creation while forcing Windows to allocate the disk space of each 128 MiB chunk immediately, otherwise, Windows would delay the allocation until we write the backup header at the end of the volume which would make the user think that the format process has stalled after progress bar reaches 100%.
We replace absolute file pointer moving by relative moving with respect to current position. This was implemented as a workaround to address the performance issues related to in-place encryption. When using SetFilePointerEx() with FILE_BEGIN as the reference point, reaching the end of large drives during in-place encryption can cause significant slowdowns. By moving the file pointer relatively, these performance issues are mitigated.
