Activating extroot on OpenWrt 12.09-rc1
Enabling extroot on OpenWrt 12.09-rc1 is bit tricky. Likely reason you're trying to enable extroot is lack of free space i.e. router with 4MB flash. Problem is that unless you're interested in creating custom firmware images there's no space left for tools to enable extroot using old procedure. Following has been tested with TP-Link MR3220 v1. It's ar71xx with 32MB RAM and 4MB flash being lowest end of currently supported OpenWrt compatible devices.