OpenWrt is the bomb. Think all the power of a full Linux distro on your tiny home router or plug computer. Install an External Root Overlay What the heck does that mean? OpenWrt uses an ingenious system were the root filesystem is a super compressed squashfs, merged with a read/write jffs2 filesystem called the overlay. This maximizes your available space on the device. Instead of using part of your remaining flash for read/write, you can use a larger, external device for the overlay.