I recently demo'ed a 4331 ISR with the SM-X-ES3-24-P module and wanted to restore the SWITCH config to factory defaults. I did an erase startup-config and reloaded (was not prompted to save the config, just a confirm of the reload), and the config was not erased. I deleted any and all config files from flash and nvram, erased startup-config and reloaded, and still no love. Attempt three was the same steps, but used the ROUTER#hw-module X/X stop and start to force the reload from within the ROUTER. Config was still there. The only way I was able to remove the configuration was by doing an erase startup-config on the SWITCH and powering off the ROUTER. I can only assume that the SWITCH config resides on the ROUTER and the configuration stays in RAM throughout the reload. Is this correct? If not, what Voodoo is being done in IOS-XE land that prevents the erase startup-config and reload process from working onthe SWITCH? I've been in the Cisco world for 20 years and have never seen that happen. Can someone explain what's going on here?
I had the same problem. After watching closely as the switch reloads, you can see it does a configuration save before reloading. There are two ways I found to get around it:
Like you said, erase the configuration on the switch and then power cycle the router. You can't use the reload command on the router because that will still cause a configuration save on the switch.
Open two sessions into the switch. In the first session, reload the switch. As soon as you see the "saving configuration" message, switch to the 2nd session and quickly erase the configuration. Because there is a minor delay before the switch reboots, it should be enough time to clear the configuration.