5 January 2022

Reset password on locked-out Domain Admin

Sometimes things happen and a password gets forgotten or lost, or in the worst case it wasn’t updated in your password management tool after it was changed. We’ve likely all had to bug another admin to reset our password for one system or another. It happens. But what happens if you are the lone Domain Admin and lock yourself out? Luckily, there is a way to get back in if you do get locked out.

  • Download the Windows Server 2016 ISO.
  • Attach the ISO to your DC virtual machine.
  • Reboot the VM into the ISO
  • Select: Repair your Computer -> Troubleshoot -> Command Prompt
  • At the command prompt, run the following commands:
cd c:\Windows\System32
ren osk.exe osk.old
copy c:\Windows\System32\WindowsPowerShell\v1.0\powershell.exe osk.exe
  • Reboot the Server.
  • Launch the on-screen keyboard and PowerShell will open
  • At the Powershell prompt, run the following command, replacing <PASSWORD> with the password of your choice:
Net user Administrator <PASSWORD>
  • Revert file changes in your System32 folder, renaming ‘osk.old’ back to ‘osk.exe’.

And there you have it folks, you are now able to log back in with your Domain Admin account. This works because while the DC does not have a local Administrator account, it somehow realizes that and resets the Domain Admin. Yes it is a little bit of black magic fuckery in that regard… But it worked and got you back in, so who are we to complain.

Category: Microsoft, Windows 2012/2012R2, Windows 2016, Windows 2019 | LEAVE A COMMENT
6 August 2021

Nutanix password change

If you leave the default passwords on your Nutanix cluster you’ll start to see alerts in Prism that the default password is still in use. It will alert you about it for both the CVM and the physical hosts. This alert is very easy to clear by just updating the password. Here’s how…

To run just the default password health check from your CVM you can use the following command:

nutanix@cvm$ ncc health_checks system_checks default_password_check

Or you can also run the complete set of NCC health checks:

nutanix@cvm$ ncc health_checks run_all

If the health check passes, you’ll see this line in the output:

/health_checks/system_checks/default_password_check              [ PASS ]

If the health check fails you’ll see this in the output and it will tell you which host(s) alerted:

/health_checks/system_checks/default_password_check              [ INFO ]
------------------------------------------------------------------------+
Detailed information for default_password_check:
Node x.x.x.x:

Nutanix Controller VM (CVM) password change

Running this command will prompt you for your new desired password for the ‘nutanix’ user on the CVM:
nutanix@cvm$ sudo passwd nutanix

Once you change the CVM’s password it will replicate to all of the CVMs in your cluster, thus changing the password on all of your CVMs at once.

Hypervisor password change

  • AHV
    To change the local “admin” account password for all AHV hypervisors in the Nutanix cluster, you can run this command from any CVM in the cluster.
    nutanix@cvm$ echo -e "CHANGING ALL AHV HOST ADMIN PASSWORDS. Note - This script cannot be used for passwords that contain special characters ( $ \ { } ^ &)\nPlease input new password: "; read -s password1; echo "Confirm new password: "; read -s password2; if [ "$password1" == "$password2" ] && [[ ! "$password1" =~ [\{\$\^}\&] ]]; then hostssh "echo -e \"admin:${password1}\" | chpasswd"; else echo "The passwords do not match or contain invalid characters (\ $ { } ^ &)"; fi
    To change the local “nutanix” account password for all AHV hypervisors in the Nutanix cluster, you can run this command from any CVM in the cluster.
    nutanix@cvm$ echo -e "CHANGING ALL AHV HOST NUTANIX PASSWORDS. Note - This script cannot be used for passwords that contain special characters ( $ \ { } ^ &)\nPlease input new password: "; read -s password1; echo "Confirm new password: "; read -s password2; if [ "$password1" == "$password2" ] && [[ ! "$password1" =~ [\{\$\^}\&] ]]; then hostssh "echo -e \"nutanix:${password1}\" | chpasswd"; else echo "The passwords do not match or contain invalid characters (\ $ { } ^ &)"; fi

  • VMware ESXi 
    To change the local root password for all ESXi hosts in the cluster, you can run this command from any CVM in the cluster.
    nutanix@cvm$ echo -e "CHANGING ALL ESXi HOST PASSWORDS. Note - This script cannot be used for passwords that contain special characters ( $ \ { }  ^ &)\nPlease input new password: "; read -s password1; echo "Confirm new password: "; read -s password2; if [ "$password1" == "$password2" ] && [[ ! "$password1" =~ [\\\{\$\^\}\&] ]]; then hostssh "echo -e \"${password1}\" | passwd root --stdin"; else echo "The passwords do not match or contain invalid characters (\ $ { } ^ &)"; fi

  • Microsoft Hyper-V 
    To change the local administrator password for all Hyper-V hosts in the cluster, you can run this command from any CVM in the cluster.
    nutanix@cvm$ echo -e "CHANGING ALL HYPER-V HOST PASSWORDS. Note - This script cannot be used for passwords that contain special characters ( $ \ { }  ^)\nPlease input new password: "; read -s password1; echo "Confirm new password: "; read -s password2; if [ "$password1" == "$password2" ] && [[ ! "$password1" =~ [\ \"\'\\\{\$\^\}] ]]; then hostssh "net user administrator $password1"; echo "Updating Host and ManagementServer Entries..."; ncli host ls | grep -i id | grep -Eo "::[0-9]*" | cut -c 3- | while read hID; do ncli host edit id=$hID hypervisor-password=$password1;done  > /dev/null; ncli host ls | grep "Hypervisor Address" | awk '{print $4}' | while read hIP; do ncli managementserver edit name=$hIP password=$password1;done > /dev/null;  else echo "The passwords do not match or contain invalid characters (\ $ { } ^)"; fi

Further info can be found in the following Nutanix KB.

Category: Nutanix | LEAVE A COMMENT