#!/bin/bash

dd if=/dev/urandom of=test_10MB.txt bs=1000000 count=10
dd if=/dev/urandom of=test_100MB.txt bs=1000000 count=100
dd if=/dev/urandom of=test_1GB.txt bs=1000000 count=1000
cat test_1GB.txt test_1GB.txt test_1GB.txt test_1GB.txt test_1GB.txt test_1GB.txt test_1GB.txt test_1GB.txt test_1GB.txt test_1GB.txt > test_10GB.txt