Overlay file system linux
From Teknologisk videncenter
								
												
				#/usr/bin/env bash
mkdir lower # Common fs 
mkdir upper1 work1 merged1   # Instance 1 fs
mkdir upper2 work2 merged2   # Instance 2 fs
mount -t overlay  overlay -o lowerdir=./lower,upperdir=./upper1,workdir=./work1 ./merged1
mount -t overlay  overlay -o lowerdir=./lower,upperdir=./upper2,workdir=./work2  ./merged2