Virtual Geek

When I began working with a new client on their Virtualization Broadcom VMware project, I encountered several ESXi servers that were already deployed and connected to vCenter servers. Since I was new to the project, I found that the root passwords for some of these ESXi servers were undocumented and unknown.

In certain cases, I needed the root password to log in and retrieve low-level information from these servers. Fortunately, if an ESXi server is connected to vCenter, it's possible to reset the root password using VMware PowerCLI, which allowed me to address the issue without direct access to the initial credentials.

Here’s a streamlined description of the script steps for resetting an ESXi root password via PowerCLI:

1. Import the PowerCLI Module: Begin by importing the VMware.PowerCLI module in PowerShell.
2. Connect to vCenter: Establish a connection to the vCenter server by logging in with the appropriate credentials.
3. Specify ESXi Host Details: Identify the ESXi host for which you need to reset the password. Typically, you will use the host name as it appears in vCenter. Specify the username (usually "root") and the new password.
4. Retrieve ESXi Information and Establish Connection: Use Get-VMHost to get ESXi host information, then create an EsxCli object using Get-EsxCLI to interact with the host.
5. Reset the Password: With the esxcli system account command, you can list and set the new password for the root account.
6. Verify Success: After successfully setting the password, a confirmation message (true) will appear, indicating the password reset was successful.

This process provides an efficient way to reset an ESXi root password for servers connected to vCenter, without needing prior knowledge of the current password.

$vcenter = 'vcenter_ip_fqdn'
$vcenterUser = '[email protected]'
$vcenterPassword = 'P@55w0rd'

Import-Module VMware.VimAutomation.Core
Connect-Viserver -Server $vCenter -User $vcenterUser -Password $vcenterPassword

###############################################################

$esxiName = 'esxi_name_from_vCenter'
$esxiUserName = 'root'
$esxiNewPassword = 'P@55w0rd'

$esxi = Get-VMHost | Where-Object { $_.Name -eq $esxiName }

$esxcli = $esxi | Get-EsxCLI -V2

$rootUser = $esxcli.system.account.list.Invoke() | Where-Object { $_.UserID -eq $esxiUserName }

$userArg = $esxcli.system.account.set.CreateArgs()
$userArg.id = $rootUser.UserID
$userArg.password = $esxiNewPassword
$userArg.passwordconfirmation = $esxiNewPassword
$esxcli.system.account.set.Invoke($userArg)

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