Recovering disks

Let's assume you backed up a whole disk (with all its volumes) and want to recover this disk to a different target platform.

The ability of the recovered system to boot up in different modes depends on the operating systems installed on the source disk. Operating systems can be convertible i.e. allow changing the boot mode from BIOS to UEFI and back, or be non-convertible. For the list of convertible operating systems, see Recovering volumes.

When a source disk contains one or more operating systems and all of them are convertible, the boot mode can be automatically changed. Depending on the current boot mode, the target disk may be initialized either to GPT or to MBR partitioning style.
If at least one operating system on a source disk is non-convertible (or the source disk contains any boot volumes of the non-convertible OSes), the boot mode cannot be changed automatically and the software will initialize the target disk as the source one. To boot up the target machine, you have to turn on/off the UEFI mode in BIOS manually. Otherwise, the system will not boot after recovery.

The following table summarizes all cases of recovering disks of a BIOS-based system to UEFI-based and vice versa.

The plus (+) sign on a green background means that the source disk will be recovered without any limitations.
The plus (+) sign on a yellow background means that the source disk will be recovered with some limitations. To overcome such limitations, you might need to perform some additional steps.
The plus/minus (+/-) signs on a red background means the disk will be recovered, but some issues might occur.


Original system	Target hardware
Platform: BIOS Target disk <2 TB	Platform: BIOS Target disk >2 TB	Platform: UEFI Target disk <2 TB	Platform: UEFI Target disk >2 TB
BIOS OS: convertible	+ The source disk will be recovered without any modification.	+ The target disk will be initialized as MBR. Limitation: only 2 TB of the disk space will be available for use. To overcome the limitation: Turn on the UEFI mode in BIOS Boot from a bootable media, and perform the recovery. As a result, the recovered OS will be converted to use UEFI for booting.	+ The target disk will be initialized as GPT. The recovered disk OS will be automatically converted to support UEFI booting. Note: If you want to recover the source disk “as is”: Turn off the UEFI mode in BIOS* Boot from a bootable media, and perform the recovery.	+ The target disk will be initialized as GPT. The recovered disk OS will be automatically converted to support UEFI booting.
BIOS OS: non- convertible	+ The source disk will be recovered without any modification.	+ The target disk will be initialized as a source one (MBR). Limitation: only 2 TB of the disk space will be available for use.	+/- The target disk will be initialized as the source one (MBR). Additional steps Turn off the UEFI mode in BIOS after recovery* Possible issue If target machine does not support BIOS, the system will not boot after recovery.	+/- The target disk will be initialized as the source one (MBR). Limitation: only 2 TB of the disk space will be available for use. Additional steps Turn off the UEFI mode in BIOS after recovery* Possible issue If target machine does not support BIOS, the system will not boot after recovery.
UEFI OS: convertible	+ The target disk will be initialized as MBR. The recovered disk OS will be automatically converted to support BIOS booting. Note: If you want to recover the source disk “as is”: Turn on the UEFI mode in BIOS. Boot from a bootable media, and perform the recovery.	+ The target disk will be initialized as MBR. The recovered disk OS will be automatically converted to support BIOS booting. Limitation: only 2 TB of the disk space will be available for use.	+ The source disk will be recovered without any modification.	+ The source disk will be recovered without any modification.
UEFI OS: non- convertible	+/- The target disk will be initialized as the source one (GPT). Additional steps Turn on the UEFI mode in BIOS. Boot from a bootable media, and perform the recovery. Possible issue If target machine does not support UEFI, the system will not boot after recovery.	+/- The target disk will be initialized as the source one (GPT). Additional steps Turn on the UEFI mode in BIOS. Boot from a bootable media, and perform the recovery. Possible issue If target machine does not support UEFI, the system will not boot after recovery.	+ The source disk will be recovered without any modification.	+ The source disk will be recovered without any modification.

Original system

Target hardware

Platform: BIOS

Target disk <2 TB

Platform: BIOS

Target disk >2 TB

Platform: UEFI

Target disk <2 TB

Platform: UEFI

Target disk >2 TB

BIOS

OS: convertible

The source disk will be recovered without any modification.

The target disk will be initialized as MBR.

Limitation: only 2 TB of the disk space will be available for use.

To overcome the limitation:

Turn on the UEFI mode in BIOS
Boot from a bootable media, and perform the recovery. As a result, the recovered OS will be converted to use UEFI for booting.

The target disk will be initialized as GPT.

The recovered disk OS will be automatically converted to support UEFI booting.

Note: If you want to recover the source disk “as is”:

Turn off the UEFI mode in BIOS*
Boot from a bootable media, and perform the recovery.

The target disk will be initialized as GPT.

The recovered disk OS will be automatically converted to support UEFI booting.

BIOS

OS: non- convertible

The source disk will be recovered without any modification.

The target disk will be initialized as a source one (MBR).

Limitation: only 2 TB of the disk space will be available for use.

+/-

The target disk will be initialized as the source one (MBR).

Additional steps

Turn off the UEFI mode in BIOS after recovery*

Possible issue

If target machine does not support BIOS, the system will not boot after recovery.

+/-

The target disk will be initialized as the source one (MBR).

Limitation: only 2 TB of the disk space will be available for use.

Additional steps

Turn off the UEFI mode in BIOS after recovery*

Possible issue

If target machine does not support BIOS, the system will not boot after recovery.

UEFI

OS: convertible

The target disk will be initialized as MBR.

The recovered disk OS will be automatically converted to support BIOS booting.

Note: If you want to recover the source disk “as is”:

Turn on the UEFI mode in BIOS.
Boot from a bootable media, and perform the recovery.

The target disk will be initialized as MBR.

The recovered disk OS will be automatically converted to support BIOS booting.

Limitation: only 2 TB of the disk space will be available for use.

The source disk will be recovered without any modification.

UEFI

OS: non- convertible

+/-

The target disk will be initialized as the source one (GPT).

Additional steps

Turn on the UEFI mode in BIOS.
Boot from a bootable media, and perform the recovery.

Possible issue

If target machine does not support UEFI, the system will not boot after recovery.

+/-

The target disk will be initialized as the source one (GPT).

Additional steps

Turn on the UEFI mode in BIOS.
Boot from a bootable media, and perform the recovery.

Possible issue

If target machine does not support UEFI, the system will not boot after recovery.

The source disk will be recovered without any modification.

* In most of the current motherboards there is a BIOS compatibility mode. So, if the system does not find any UEFI boot loader it will try to boot system in BIOS mode.