dep composed on 2024-09-02 20:50 (UTC):
Advice?
ESP (Efi System Partition) must be at least 32MB. Windows' minimum is 100MB. With a 4k sector drive of more than 16TB, minimum is 260MB.
Using Grub for booting in Debian 12, 32MB would be far more than adequate. Using systemd-boot instead of Grub, the ESP must be magnitudes larger, probably at least 1000MB, because when using systemd-boot the kernels and initrds live on the ESP in /boot/efi/ instead of in /boot/ directly.
I use only Grub. All my ESPs are 320MB on multiboot PCs, with less than 10% of space in use on each of them. The file (normal boot) or files (secure boot) used by Grub live on the ESP and are loaded by the UEFI by their filename(s) on the FAT32 ESP filesystem.