#1141764 Should maybe have guidance on recommended ESP size for UEFI systems

Package:
src:installation-guide
Source:
src:installation-guide
Submitter:
Steve McIntyre
Date:
2026-07-19 11:25:01 UTC
Severity:
normal
Tags:
#1141764#5
Date:
2026-07-09 22:10:23 UTC
From:
To:
Checking https://www.debian.org/releases/trixie/amd64/install.en.txt,
we don't have any guidance here for ESP size. We probably should. d-i
defaults to 768 MB these days, but people might go smaller and run
into problems with fwupd and/or UKIs later. Let's help people avoid
those problems.
#1141764#10
Date:
2026-07-11 15:47:03 UTC
From:
To:
Hi all,

Am 10. Juli 2026 00:10:23 MESZ schrieb Steve McIntyre <steve@einval.com>:

A proposal, adding an (identical) note to 6.3.4.2 (guided partitioning) and
6.3.4.3 (manual partitioning), two places, where we are talking about ESP:

----------------------------------------------------------------------------------------
To be future-safe, you should not go with an ESP partition smaller than 768-1000 MB
these days. Otherwise you risk running into problems, when it comes to kernel upgrades
via UKIs or firmware upgrades of your PC's devices later.

By the way: the same size recommendation counts for /boot as well (if you spend a
separate partition for /boot).
----------------------------------------------------------------------------------------


Since we have a similar issue with /boot, I have added the second sentence, BTW.


Patch attached.

Comments?


Holger
#1141764#15
Date:
2026-07-11 16:22:47 UTC
From:
To:
Hi,

Holger Wansing <hwansing@mailbox.org> wrote (Sat, 11 Jul 2026 17:47:03 +0200):

And if we recommend 768-1000 MB for ESP and /boot, we should better not have an
example partition list with a 16 MB /boot partition :-))


I have updated the example to this century. Patch attached.


Holger
#1141764#20
Date:
2026-07-11 21:26:52 UTC
From:
To:
Or if you use systemd-boot and the Boot Loader Specification (BLS)
layout. The BLS requires to install kernel and initramfs images into the
ESP (unless you have a separate Extended Boot Loader partition on the
same drive mounted on /boot but this is not supported by Debian kernel
packages yet AFAIK).
#1141764#25
Date:
2026-07-14 18:51:46 UTC
From:
To:
Hi,

Pascal Hambourg <pascal@plouf.fr.eu.org> wrote (Sat, 11 Jul 2026 23:26:52 +0200):

I think it's getting overly technical and complicated, if we mention this
as well IMHO.


Holger
#1141764#30
Date:
2026-07-14 19:15:01 UTC
From:
To:
Maybe just mention systemd-boot, which is already offered by d-i in
expert mode as an alternative to GRUB on supported architectures ? The
rest was only technical details for the discussion.
#1141764#35
Date:
2026-07-14 20:42:24 UTC
From:
To:
Hi,

Pascal Hambourg <pascal@plouf.fr.eu.org> wrote (Tue, 14 Jul 2026 21:15:01 +0200):

So I could think about something like:

To be future-safe, you should not go with an ESP partition smaller than 768-1000 MB
these days. Otherwise you risk running into problems later, when it comes to
kernel upgrades via UKIs, firmware upgrades for your PC's devices, or when
when you use systemd-boot with BLS layout.


Holger
#1141764#40
Date:
2026-07-14 21:44:44 UTC
From:
To:
   ^^^^
Duplicate "when". Otherwise, LGTM.
#1141764#45
Date:
2026-07-19 11:20:17 UTC
From:
To:
Hi,

Pascal Hambourg <pascal@plouf.fr.eu.org> wrote (Tue, 14 Jul 2026 23:44:44 +0200):

Just pushed to git.

Holger
#1141764#50
Date:
2026-07-19 11:23:54 UTC
From:
To:
Holger Wansing <hwansing@mailbox.org> wrote (Sun, 19 Jul 2026 13:20:17 +0200):