[systemd-devel] why does bootctl default to /boot and not to /boot/efi?

[Chris Murphy]

On Wed, Jun 1, 2016 at 10:13 PM, Mantas Mikulėnas <grawity at gmail.com> wrote:
> Hmm, I thought Windows creates a 512 MB ESP by default (as per MS's own
> recommendations)?

It depends on the OEM. Few installations are done by users/admins,
Windows is pre-installed and the restore software is OEM specific, and
typically isn't customizable. You point it at a drive, and it
obliterates the drive in favor of the restore image layout. On a
recent Dell it was 100MB for the ESP.

For 512 byte sector drives, Microsoft says the minimum is 100MB. Many
OEMs use exactly 100MB. Microsoft's own Windows 8 and Windows 10
installers use 100MB.
https://technet.microsoft.com/en-us/library/dd799232%28v=ws.10%29.aspx

For 4kN drives, they're made 260MB.

For years now distros have made a separate /boot partition 500MB.
RH/Fedora Anaconda team is planning to make it 1GB, due in part to
people running out of space with 500MB on RHEL apparently (for reasons
I can't track down other than it appears kdump expects to be able to
dump its images directly onto /boot which seems like a bad idea
whether or not /boot is an ESP).

So really no matter how you cut it, it's not workable, broadly, for
dual boot, unless you keep just a couple kernels and always make
hostonly initramfs or no initramfs. But if you're designing something
for "most" people, you have to take common lowest common denominator
cases into account and right now sd-boot doesn't do that.




-- 
Chris Murphy