Trying to write a program to fill up my harddrive (Linux/C)

Applications Programming
1

Hi guys, I'm trying to write a little program that will fill up my harddrive and will log the process during this.

Now I've come up with this:

#include <stdio.h>
void main(void) {
    char cmd1[100];
    char cmd2[100];

    int i=1;
    sprintf(cmd2, "df -h");

while (i<=5)
{ 
    system("dd if=/dev/zero of=/pagefile-%i bs=1024 count=100000", i);
    system(cmd2);
i++;
}

}

But for some reason it only copies the file I make once and then just keeps overwriting it. I tried adding a variable so it would change the name and not overwrite the previous file but it still doesn't work.

Any suggestions?

(sorry if this is the worst programming you've ever seen)
Big thanks!

2 
#include <stdio.h>
#include <stdlib.h>
int main(void) {
    
    char cmd2[100]={0x0};
    char cmd1[256]={0x0};
    int i=1;
    sprintf(cmd2, "df -h");

while (i<=5)
{ 
    sprintf(cmd1, "dd if=/dev/zero of=/pagefile-%i bs=1024 count=100000", i++);
    system(cmd1);
    system(cmd2);
    
  }
   return 0;
}

You do realize this is a bad idea. You may "freeze" your system
if you are doing this on the root filesystem/partition.

Other than filling a disk what are you trying to accomplish?

3

just that, thanks man, I was just trying to write some programs that will stress my system. Like max out CPU power and max out network etc...

I'm studying for some exam and we might have to write a program like that ourselves so I was trying to make one myself.

Thanks for your help mate!

4

Too straight forward Jim :smiley: I want that last fs block even if the fs has a silly 2 byte block size :slight_smile:

#include <stdio.h>
#include <errno.h>
#include <sys/vfs.h>
#include <stdlib.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <fcntl.h>

#define MAX_PHYSIO 128		/* size of phsyical io in blocks */

char *outbuf; 

struct statfs vbuf;

int  main() {

int tickle = 5;  /* how often to print progress based on number of writes  */
int count = 0;
int fd;
long outsize;
int j;

/* create the file */

if( (fd = open("fill.all", O_CREAT | O_WRONLY)) < 0 )
{
	perror("fill.all: ");
	exit(fd);
}

/* get filesystem info */

fstatfs( fd, &vbuf);

outsize = vbuf.f_bsize * MAX_PHYSIO;		/* calculate output size */
outbuf = (char *) malloc(outsize);		/* allocate the buffer */
printf("Free blocks: %d\nOutput Buffer size: %d\n", vbuf.f_bfree, outsize);

j = tickle ;  

while( write(fd, outbuf, outsize) > 0 )
{
	if ( j == 0)
	{
		fstatfs(fd ,&vbuf);
		printf("Blocks left: %d\n", vbuf.f_bfree);
		j = tickle;
	}
	else
		j--;
}

fstatfs( fd, &vbuf);

if (vbuf.f_bfree > 0)
	write(fd, outbuf, vbuf.f_bfree);

printf("done\n");
}

For extra fun you can add an fsync() call after the last write call. Could lock up your system for a bit ... depending on your RAID type and implementation :smiley: