i cant login to a esxi host. dont have the root password. what are my options to reset the password?
Officially;
Changing a forgotten root password on an ESX/ESXi host (1317898) | VMware KB
Resetting a forgotten root password in ESXi 3.5, ESXi 4.x, ESXi 5.x and ESXi 6.x isn't supported and VMware advocate a re-installation.
Unofficially there may be some options to investigate with Host Profiles and Active Directory...
Three ways to reset a VMware ESXi root password – 4sysops
Best of Luck
Simon
As per the VMware official documents, there is no option to reset the root account password, you have to reinstall the ESXi.
However, if the host is part of vCenter then you can try the following workaround
https://www.vladan.fr/how-to-reset-esxi-6-x-root-password-and-under-which-conditions/
http://blog.clearpathsg.com/blog/bid/301156/Lost-Your-ESXi-Root-Password-Reset-It-with-Host-Profiles
the host is disconnected from vcenter. will upgrading the host provide an option to reset password?
Not possible during the upgrade. You should completely reinstall the ESXi
Here's a link to maybe try a few things. But I think the official supported method is to reinstall ESXi.
Thanks for the information
