RAM Disks in OS X

If you’ve ever wanted to set up a ramdisk in Mac OS X, here’s a quick script you can use. Simply invoke it with a size in MB and the name for your volume and it will create and automount it for you. It also won’t leave any dangling directories in your /Volumes/ when you eject it! Be sure to chmod the file you place the script in to make it executable (755 or likewise).

#!/bin/bash
if [ -n "$3" ]; then NUM_ARG=ERR; fi
if [ -z "$1" ]; then NUM_ARG=ERR; fi

if [ -n "$NUM_ARG" ];
then
echo 'Usage: ./ramdisk  <name, optional>'
exit
fi
SIZE=$1
NAME='my_ramdisk'
let "SIZE *= 2048"
if [ -n "$2" ]; then NAME=$2; fi
diskutil erasevolume HFS+ "$NAME" `hdiutil attach -nomount ram://${SIZE}`
echo 'Done'