During an upgrade from VCSA 6.5 to 6.7, the following error was observed in the install log and prevented stage one of the upgrade from starting.

  • Unable to contact the source vCenter
  • Failed To Authenticate With The Guest Operating System Using The Supplied Credentials.

##To see the complete upgrade process from vCentre 6.5 to 6.7, refer to our blog < https://www.hex64.net/upgrading-vcenter-server-6-5-to-vcenter-server-6-7-using-vcsa-ui-installer/ >


  • Upgrading vCenter Server Appliance from 6.5 to 6.7 fails with the error:

Error: sourcePrecheck: error in getting source Info: ServerFaultCode: Failed to authenticate with the guest operating system using the supplied credentials.

  • In installer-xxxxxxxx-xxxxxxxxx.log you may see entries similar to:

Upgrading vCenter Server


While upgrading vCemtre server, there is a step to connect to the existing vCentre server and this error prevents connection to the existing vCentre server. You need to resolve it to complete the stage 1 of the upgrade process.

existing vCentre server

This issue occurs when the vCenter OS password (root password) is expired.

To resolve this issue, reset the password:

To reset the password:
1. Connect to the source vCenter using SSH.

source vCenter using SSH

2. Execute “chage -l root” command to check if the root password has expired.

3. Change the password using the command “passwd”

4. Initiate the upgrade again.