How to reset ESXi root password from iDRAC (v.7) for Dell PowerEdge R720?
Is it possible?
As per vmware documnetaion
Reinstalling the ESXi host is the only supported way to reset a password on ESXi. Any other method may lead to a host failure or an unsupported configuration due to the complex nature of the ESXi architecture.
Now if you can take the risk then check ESXi - Reset the password for root . This use a Slax Linux Live CD to reset the password.