Reset vCenter Appliance root password

To reset the root user password in the vCenter Boot the virtual appliance and navigate to the console for the virtual machine in the vSphere Client. Click in the console and press any key to display the GRUB menu. 

Note: The GRUB prompt remains on screen for few seconds before it starts the boot sequence. 

On the GRUB menu, select SUSE Linux Enterprise Server for VMware.

Type e to edit the line. A list of items in the GRUB configuration file appears.

Select the line that starts with kernel and type e to edit the line.

At the end of the line, press the spacebar and type init=/bin/sh.

Press Enter to exit edit mode.

On the GRUB screen, type b to boot into single-user mode. 

The virtual appliance boots in single-user mode.

To change the root user password, type passwd root and follow the on-screen prompts.

To restart the virtual appliance, type reboot and press Enter.

When the virtual appliance restarts, you can log in using the new password.

Troubleshooting the vCenter Server Appliance with Single Sign-On login

Details

The two most common network-related problems when connecting to a vSphere Server Appliance using the Web Client and Single Sign-On (SSO) are SSL certificate failure and a changed SSO server IP address. These errors are seen when the problem is encountered:

• Failed to connect to VMware Lookup Service https://<vCVA IP address>:7444/lookupservice/sdk - SSL certificate verification failed. 
• Failed to communicate with the vCenter Single Sign On server https://<vCVA IP address>:7444/ims/STSService.

Solution

If the SSO SSL certificate failed, the network identification for the vSphere Server Appliance has changed, but the SSO SSL certificate has not been updated to match it. For instructions on changing the certificate, see the technical note Replacing Default vCenter 5.1 and ESXi Certificates. 

To resolve this issue, toggle the certificate settings:

1. Log in the vCenter Server Appliance Web interface at https://hostname:5480/.
2. Click the Admin tab.
3. Regenerate certificates by selecting Toggle certificate setting. The Certificate regeneration enabled option under the Administration settings displays Yes.
4. Reboot the vCenter Server Appliance.

Notes: 

• vCenter Server generates new default certificates using this option. For systems that use custom certificates, you must regenerate the certificates manually.
• Regeneration of default certificates may take a long time to complete. For more information, see Rebooting vCenter Server Appliance 5.1 takes a long time when regenerating SSL certificates (2058332).