Hybrid partition table

Most x86 and x86_64 systems only use either the MBR (MS-DOS based) partition table layout, or the GPT (GUID Partition Table) layout. However, in certain situations it might be necessary for a GPT partition layout to have an "MBR view" overlayed. This is called Hybrid MBR/GPT.

Using hybrid partition table
Using a hybrid partition table might be necessary when dual-booting operating systems that are blind to a GPT-partitioned disk. In these situations, the partition definition requires a tricky workaround.

Creating with gdisk
Creating a hybrid MBR is easy using : at the main menu press the key (for recovery and transformation), then press  key (CHS recompute), then enter the series of partitions (less or equal to 3) in the order they should be be listed in the MBR. Finally enter the hexadecimal partition type without the  prefix or accept the defaults by repeatedly pressing the  key.

Enable only a single boot flag as found the following example:

GRUB2
GRUB2 supports booting from GPT and MBR partition tables via the  and   modules. However, a successful setup and GRUB2's ability to boot correctly depends both on loaded partition modules and on correctly installing GRUB2. A determining factor in how GRUB2 is installed (BIOS-MBR vs BIOS-GPT) is the presence of a EE00 (GPT protective) partition as the first partition in the MBR.

With a hybrid MBR, GRUB2 will install if the first partition in the MBR table is an  partition. An  partition should be present anywhere in the disk and not necessarily in the MBR list. Leave enough open sectors before the first partition!

GRUB2 requires an  partition type at the first listing in the MBR partition list entry, however it may pose a problem when booting other operating systems on the same disk (especially Windows). A workaround is available in order to recognize a GPT partitioned disk with (or without) hybrid MBR. Removing any protective  partition with the  command.

Use other disk tools such as  or   to resize after that. Otherwise use to add protective   partitions to protect at least GPT main and backup the partition before using any non-GPT aware tools if necessary.

Another issue should be addressed when attempting to use a GPT Hybrid MBR configuration: Windows MSDOS based bootloaders) may not find suitable partitions to boot from if there is a  partition protecting the GPT main partition table (sectors 1-2047). If this happens remove the protective   partition before getting a valid MBR partition list in [MS]DOS tools (to format a partition for example, the tools recognized a GPT partitioned disk at least). And then use  to recompute the CHS value for hybrid MBR (in the recovery and transformation menu, or in the expert section of 's main menu).