What does this yast warning means?
"The system might not be able to boot:
A partition of type BIOS Boot Partition is needed to install the bootloader.
Such a setup is not supported and may cause problems with the bootloader now or in the future.
Do you want to continue?"
I like to use the partition scheme as follow.
swap 2 gb
/ 40 gb
/home all the rest
But I get the warning error above.
When you partition in GPT mode for legacy/BIOS booting you must have a tiny BIOS boot partition where a bootloader can be installed instead of the MBR track where Grub most often gets installed for legacy booting. With GPT partitioning and UEFI booting, the required VFAT ESP partition provides an equivalent home for boot instantiation.
It might work. Or it might not work.
If you are using disk encryption, it won’t work. If you are not using encryption, but you are using “btrfs”, then it might work if it is set to boot from a partition, but it won’t work booting from the MBR. If you are use “ext4” for the root file system, it will probably work.
With older legacy BIOS partitioning, when you boot from the MBR the bootloader also uses a chunk of disk space near the MBR that is not allocated to a partition. But you are using GPT partitioning, where that isn’t allowed. So the BIOS boot partition provides the additional disk space that the bootloader needs.
With “ext4” and no encryption, the amount of space needed by the bootloader is relatively small and it usually can fit in just the MBR. If you are using “btrfs” and no encryption, then the “btrfs” partition sets aside space for a boot block. But if you are using an encrypted disk, then the bootloader needs more space to handle the crypto, and it won’t work without the BIOS boot partition.
No, it cannot. Ever. The available space in MBR is 440 bytes and there is no way grub can fit there (just grub kernel itself without any additional modules is already 29K and is very unlikely to compress to several bytes.
The only code that resides in MBR itself is the code to read core.img from disk using absolute disk location(s).
So, there are two scenarios, GPT with legacy boot support where the Bios type partition is requiered and GPT UEFI where it is not, and the ESP is requiered instead, am I right?, how can I create manually this partitions in each scenarios?, I own a Intel DH61WW motherboard, If I enable UEFI mode with no legacy support, will I get rid of the warning?
Thanks
Hi
If your system can boot UEFI (which I would suggest), then;
sda1 - type ef00 size 260M format fat
sda2 - type 8300 size 40G /
sda3 - type 8300 size ?? /home
sda4 - type 8200 size 2GB swap
For legacy;
sda1 - type ef02 size 8M (BIOS boot)
sda2 - type 8300 size 40G /
sda3 - type 8300 size ?? /home
sda4 - type 8200 size 2GB swap
This is gdisk output from the above setup for a laptop I have here;
Number Start (sector) End (sector) Size Code Name
1 2048 18431 8.0 MiB EF02
2 18432 83904511 40.0 GiB 8300
3 83904512 247482367 78.0 GiB 8300
4 247482368 250069646 1.2 GiB 8200
I haven’t seen again this annoying warning since switching all my systems to gpt / uefi in 2015: Frühjahrsputz | Karl Mistelberger