Create RAM Disk for OS X

create_ramdisk.sh

#!/bin/bash

size=1024

usage() {
    echo "$0: Create RAM Disk with given size(default is 1024MB)"
    echo "    e.g.: $0 512"
    exit 1
}

if [[ $# -eq 1 ]]; then

    size=$1

    re='^[0-9]*$'
    [[ ! $size =~ $re ]] && usage $0
else
    usage $0
fi

sector=`echo "$size * 4 * 512" | bc`

echo "Create ${size}MB RAM Disk"
diskutil erasevolume HFS+ 'RAMDisk' `hdiutil attach -nomount ram://$sector`