(deprecated - look here https://gist.github.com/fbrnc/11296418)

shared_memory.sh

#!/bin/bash
if [ ! -d $1/var ] ; then echo "Invalid directory $1/var"; exit 1; fi

SHMFOLDERS=( "full_page_cache" "cache" "session" )

for i in "${SHMFOLDERS[@]}" ; do
        if [ ! -d $1/var/$i ] ; then echo "Invalid directory $1/var/$i"; exit 1; fi
        if [ -d /dev/shm/$i ] ; then echo "Directory /dev/shm/$i already exists"; exit 1; fi
        mv $1/var/$i /dev/shm/$i
        ln -s /dev/shm/$i  $1/var/$i
        chown -R vagrant:www-data /dev/shm/$i
        chmod -R ug+rw /dev/shm/$i
done