I've just inherited a very simple VM setup with a pair of ESXi servers clustered and everything is pretty much hooked up. Problem is I do not have the root passwords for the servers and no one has any idea what they are (password guessing has been tried).
From my understanding, ESXi does not have a single-user mode or anything equivalent. What are my options short of backing up the VMs and nuking the site?
Best Answer
For ESXi, the only supported method to change the password is to reinstall.
If you have two hosts and they have the resources to support it, you could vMotion (and/or storage vMotion) the servers all onto a single host, remove and rebuild the empty host, add it back into the cluster. Then move all the guests onto the rebuilt host and remove/rebuild the remaining host. This would allow you to rebuild without incurring any downtime on the guests. Depending on your infrastructure and depending on the number of virtual machines to move, the two hosts should take less than a day to rebuild unless you have extraordinarily large or complex host configuration.
Also, if you are on an older version of ESXi, this would also be a good time to check your current hardware against the HCL and move up to the latest version if supported (After upgrading your vCenter server first of course).
Regarding non-supported methods that I will mention but don't necessarily advise.