On 09/20/2017 08:17 PM, Lennart Sorensen wrote:
On Wed, Sep 20, 2017 at 06:04:16PM +0200, Pierre Couderc wrote:
Mmm, why ? is legacy mode a problem ?
Well depends what you want to do. Generally legacy mode requires the
disk be partitioned in DOS style partitions (MBR) which has a limit of
2TB disks, while UEFI requires GPT which does not have that limit.
Also you are limited to 4 primary partitions with MBR, while GPT allows
128 partitionts. You can get past the 4 primary limit with extended
partitions, but they are a hassle sometimes.
UEFI booting is probably more future proof if you want to be able to
move a disk to another system later, although at the same time MBR is
more legacy machine compatible.
UEFI does not support installing the boot loader on a software raid
partition and having it work as simply as MBR did with grub. It has to
be a plain partition on the disk of the type ESP with FAT32 or other
compatible filesystem, which is a bit annoying. It might be possible
to do a software raid partition for that if you pick the type that has
the meta data at the end (but that is not the default), since then it
would still look like a normal disk to the firmware.
Well, thank you for this clear explanation. In fact, I see no reason to
use UEFI mode while I have a full btrfs RAID1 system who works fine now
in legacy mode,
with 2 disks and only 1 btrfs partition each 2T disk.
And I hope it is for 5 years...
Thank you very much for your help.
