Hello Rama Krishna -- This is a very valid point and a good question.
Generally speaking you should know that when an IOx application is installed there are intermediate steps being performed. During that time the peak disk usage is more than what you see after installation. We typically say that you need 4 times to uncompressed application size space left (we have improved that number on the latest Docker-based images).
Meanwhile the IOx Sandbox is probably using a recent Docker-based IOx engine, whereas the IR829 is still using LXC-based engine. It does not run Docker natively but instead uses libvirt. They are intermediate steps to be taken during IOx application that will increase the disk space usage up to a point where disk space is lacking.
Couple of pointers:
a) Make sure that you have deleted all Docker layers in Local Manager before trying a new installation.
b) Try to reduce your IOx application size by trimming what's not needed. This is not aways easy.
c) Break down your big container in multiple smaller containers
d) Unfortunately not available in India, but we have a 100GB SSD disk available for IR829 to deal with bigger IOx apps.
Emmanuel