Re: [List] EFI partition size

On Fri, Dec 5, 2025 at 12:08 PM Frank Leonhardt <freebsd-doc@fjl.co.uk>
wrote:

> On 04/12/2025 18:09, Michael Grimm wrote:
>
> Hi,
>
> I used to set the EFI partition size to 100 M for the past years.
>
> Today I tested the installer on Hetzner's FreeBSD 15.0-RELEASE image at https://www.hetzner.com/cloud/ and found the installer setting this EFI partition size to be about 260 M.
>
> Well disk size is cheap nowadays, but what would be a reasonable partition size for the next years to come?
>
> Thanks and regards,
> Michael
>
> Hi Michael,
>
> FreeBSD used to use a relatively small EFI partition: <1Mb. I've noticed
> it getting larger. The only reason I can think of is so you can store more
> stuff on it like firmware update tools and alternative bootloaders (for
> other operating systems) - they've got to go somewhere outside the OS
> partitions.
>
> It's a good question. My guess is you don't need nearly as much if you're
> using the disk for nothing but FreeBSD. There's still time for someone who
> knows the inside story to answer.
>
> You can look at the EFI partition easily enough, being FAT. There's
> usually about 1-2Mb in there. I'd say allow 4Mb to be safe. Maybe 8Mb to be
> extremely safe. The worst that can happen is you need to install more
> bootloaders and have to expand it, which would be a PITA but you'd also
> need space on the disk for more operating systems and you're probably
> setting the whole drive up for FreeBSD anyway.
>
> Regards, Frank.
>
>
Frank is entirely correct.  I run my ARM64 EC2 instances with an 8M EFI
boot partition.  It's overkill, but it allows for flexibility if I want to
include silly things later on.

/boot/efi/efi/boot/BOOTaa64.efi : 393216 bytes

1. Name: nda0p1

   Mediasize: 8388608 (8.0M)

   Sectorsize: 512

   Stripesize: 4096

   Stripeoffset: 0

   Mode: r1w1e1

   efimedia: HD(1,GPT,d012c8df-f675-11ee-8a96-7fb2188a5702,0x28,0x4000)

   rawuuid: d012c8df-f675-11ee-8a96-7fb2188a5702

   rawtype: c12a7328-f81f-11d2-ba4b-00a0c93ec93b

   label: boot

   length: 8388608

   offset: 20480

   type: efi

   index: 1

   end: 16423
   start: 40