At some point you may find it necessary to reset the configuration of your ESXi host. A full reinstall may not be warranted plus you may want to preserve an existing local VMFS datastore. When you reset the configuration of your host any configuration changes made will be removed and the password will be deleted for the root account. After the reset is complete and your host is rebooted you'll want to make any configuration changes to your vSwitches, datastores, etc. To add VMs back into inventory, right click on the datastore, select browse, find the VMX file and then right click and select Add To Inventory. Note that if you've changed the name of virtual machine port groups or make changes to your VMDirectPath configuration, you'll want to edit each VM affected to ensure you have the correct settings. If for example you had a port group called DMZ_1 before the reset and it was called DMZ_A after, when you add your existing VMs they will still be configured to connect to DMZ_1 and will have to be updated to use DMZ_A.
Below is the process for doing a reset at the DCUI. If you want to do this via SSH, you can use the command /sbin/firmwareConfig.sh. With the --reset-only option the configuration will be reset and you'll have to manually reboot the host. If you choose --reset then the configuration will be reset and the host will be rebooted. With this option you'll see the message "config explicitely loaded" and the host will then reboot.
1) Login to the DCUI and select the Reset System Configuration Option.
2) You will be prompted to confirm the option with F11.
3) The process will complete and you'll then have to reboot the host.
Copyright © 2011 - Dave Mishchenko