Re: Problem with grub-install (d-i, soft RAID6, Jessie)
Christian Seiler a écrit :
>
> Well sure, but MBR also has all the CHS baggage - and while it isn't
> used anymore on modern systems, there still is the de-factor standard
> of aligning the first partition with the first CHS-sector that is so
> ingrained historically that the gap between MBR and the first
> partition is something that may be relied on.
Even in the MBR/MSDOS partition table scheme, the alignment is not based
on CHS pseudo-geometry any more.
> Or to put it differently: because of the CHS baggage of MBR, there
> is software that wouldn't support it if the first partition wasn't
> aligned;
Only very old software.
> for compatibility reasons every tool that manipulates MBR
> partitions will therefore want to leave a gap after the MBR.
Current tools won't align for compatibility purpose any more. The
default 1-MiB alignment is only for performance purpose, not compatibility.
> So yes, my statement was an oversimplification - but it is not
> unreasonable to have a gapless disk with GPT - hence the
> explanation why grub doesn't use this gap anymore. (Because you
> could also create a partition there afterwards.)
Or grow the partition table and overwrite the gap.
>>> At least Jessie's d-i appears to only be able to create MBR
>>> partition tables
>> That's wrong. I have created GPT partition tables with Wheezy's
>> installer. IIRC, it creates a GPT partition table by default when booted
>> in EFI mode.
>
> I didn't try EFI mode recently. But in legacy BIOS mode, I've found
> no option of making the installer create a GPT table - I actually
> had to use a shell to do it manually. (If there is an option, it's
> *too* well hidden.)
Maybe you have to select "expert install" at the boot menu.
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