Restore the Virtual BIOS or UEFI

The .nvram file stores the BIOS or UEFI customizations of a virtual machine. Usually the only important items in this file are the boot drive setting and the boot order (in the case of multiple virtual disks).

Newer releases of vSphere can change the boot order using extended attribute settings, so boot order no longer must be stored in the .nvram file. However some users want to preserve a virtual machine’s serial port settings in the .nvram file, and possibly other items, so applications should back up and restore this information.

To back up and restore NVRAM:

Procedure

  1. For each virtual machine, make a separate copy of the .nvram file.
  2. Back up each virtual machine using standard methods.
  3. If necessary, restore the virtual machine using standard methods.
  4. Overwrite the virtual machine’s .nvram file with the saved copy of the original .nvram file.
    Important: VMware now recommends saving the .nvram file as part of virtual machine backup, a change in recommendation since vSphere 4.1.