After you install ESXi on a host machine in UEFI mode, the machine might fail to boot.
Problem
When you install or upgrade ESXi, the installer tries to create an UEFI boot option named VMware ESXi and make it the default boot option. When you reboot after installing ESXi the reboot might fail. This problem is accompanied by an error message similar to No boot device available.
Cause
- When the installer creates the UEFI boot option, a problem occurs while writing to the NVRAM on the host motherboard.
- The host firmware does not recognize the attempt to set the UEFI boot option as the first boot option, or the firmware overrides the boot order.
- The boot disk has an MBR or MSDOS partition table. Due to a technical limitation, the UEFI boot option is only created for a GUID Partition Table (GPT) partition table.
Note: UEFI firmware attempts to load the boot image from the EFI system partition, which is FAT based, on the disk. Booting from the EFI system partition only works if the disk is laid out by using a GPT. If the boot disk has an MBR or MSDOS partition table, a UEFI boot fails. You cannot add a boot entry for MBR. If the disk is fully consumed by ESXi, it cannot be converted to GPT, and you must boot in legacy BIOS mode.