Quickly create large file on a windows system?

Question

In the same vein as http://stackoverflow.com/questions/257844/quickly-create-a-large-file-on-a-linux-system I'd like to quickly create a large file on a windows system. By large I'm thinking 5GB. The content doesn't matter. A built in command or short batch file would be preferable, but I'll accept an application if there are no other easy ways.

Answer 1

Check the windows resource kit.

http://www.microsoft.com/Downloads/details.aspx?FamilyID=9d467a69-57ff-4ae7-96ee-b18c4790cffd&displaylang=en

There is a utility called

 CREATEFIL.EXE
 -? : This message
 -FileName -- name of the new file
 -FileSize -- size of file in KBytes, default is 1024 KBytes

It is the similar to mkfile on solaris.

Answer 2

Short of writing a full application, us Python guys can achieve files of any size with 4 lines, same snippet on Windows and Linux (os.stat() line is just a check).

>>> f = open('myfile.txt','w')
>>> f.seek(1024-1) # an example, pick any size
>>> f.write('\x00')
>>> f.close()
>>> os.stat('myfile.txt').st_size
1024L
>>>

Answer 3

I found a solution using DEBUG at http://www.scribd.com/doc/445750/Create-a-Huge-File, but I don't know an easy way to script it and it doesn't seem to be able to create files larger than 1 GB.

Answer 4

You can use the Sysinternals Contig tool. It has a -n switch which creates a new file of a given size. It will create a file almost instantaneous.

Answer 5

/*
creates an empty file, which can take 
all of the disk space. Just specify the desired file
size in the command line
*/
#include <windows.h>
#include <stdlib.h>
int main (int argc, char* ARGV[])
{
    int size;
    size = atoi(ARGV[1]);
    const char* full = "fulldisk.dsk";
    HANDLE hf = CreateFile(full, 
                           GENERIC_WRITE, 
                           0,
                           0,
                           CREATE_ALWAYS,
                           0,
                           0);
    SetFilePointer(hf, size, 0, FILE_BEGIN);
    SetEndOfFile(hf);
    CloseHandle(hf); 
    return 0;
}

Answer 6

fsutil file createnew <filename> <length>

where <length> is in bytes.

Answer 7

Blooming Big File. Google it. It quickly creates big files on Windows machines.

Answer 8

Hey i know this is an older thread but i was wondering if any of you would know how to make an incremental naming solution for this .bat file Leigh was working on here. for instance if you had contig -n I:\SpaceBuffer.tmp 5368709120 and you wanted to make it do a loop:

set number for (parameters) {

contig -n I:\SpaceBuffer%number%.tmp 5368709120 number++ } How would someone do this in a .bat file. I have taken intro Comp Sci classes in school but honestly i'm complete rubbish at programming and unless i've seen something hashed out for me I really can't do it.

Answer 9

In cmd prompt: fsutil file createnew c:\temp\100MBfile.txt 104857600