With all new dedicated root server models, Hetzner Online will support UEFI boot natively and discontinue legacy boot (CSM) support. UEFI Rescue System is currently in the BETA stage.
UEFI (Unified Extensible Firmware Interface) is the replacement for the legacy BIOS firmware.
At this time (2020/03/19), all servers which we currently have in our new dedicated root server portfolio support a stable UEFI boot including the Hetzner Rescue System.
UEFI gives customers several advantages, like using large disks partitions over 2 TB with GPT, a flexible pre-OS environment and backward/forward compatibility, and also an easier way to setup a dual boot. Also, if a failed drive has to be replaced, the drive only needs to get re-mounted into the RAID. There is no need to install the bootloader on the harddisk: the bootfiles are on a separate FAT formatted partition, which is in a RAID in our images. For more information about this, see EFI system partition
Customers can open a ticket on the administration console Robot. Navigate to the correct server and open a support ticket. In it, ask the support team to enable UEFI on the server. Important note: There will be a short outtage when the support team enables the UEFI support on the server. Also, the installed operating system must have UEFI support, and you need an EFI system partition to boot the system.
The CSM (Compatibility Support Module) will be disabled completly, so you will not be able to a UEFI-CSM compatible system.
In Linux, there are two ways to check if the system is running in UEFI mode.
efibootmgr on a UEFI-enabled system will give you an output like this:
BootCurrent: 0019 Timeout: 1 seconds BootOrder: 0019,0000,004,0005 Boot0000* UEFI OS: Samsung MZVLB512HAJQ-00000 Boot0004* UEFI:Removable Device Boot0005* UEFI:Network Device Boot0019* UEFI: IP4 Intel(R) Ethernet Connection (2) I219-LM
efibootmgr on a non UEFI-enabled system will give you an output like this:
EFI variables are not supported on this system.
If the path
/sys/class/firmware/efi/ exists, then the system is UEFI-enabled.
System Information) and check under
System Summary -> BIOS Mode to see if it says
We know about the benefits of Secure Boot and also that some customer want to use Secure Boot. You can enable it, but we do not support it. If you enable it, the rescue system and automatic installation will not be available anymore, and the system might not be bootable anymore (Linux-based distributions).
As UEFI boot is still in the BETA stage, we cannot assure that a hardware-RAID controller is compatible with UEFI boot.