Arch Linux

tobru

Member

Registered: 2022-01-10

Posts: 3

GRUB very slow loading Kernel and Initramfs from encrypted /boot

I created and encrypted /boot partition and configured GRUB to support that setup, as documented here https://wiki.archlinux.org/title/Dm-cry … ion_(GRUB). While the system properly boots, it's very slow at the stages where GRUB loads the Kernel and Initramfs:

grub> testspeed (crypto0)/vmlinuz-linux
File size: 10.49MiB
Elapsed time: 10.222 s 
Speed: 1.03MiB/s

grub> testspeed (crypto0)/initramfs-linux.img
File size: 21.96MiB
Elapsed time: 20.430 s 
Speed: 1.07MiB/s

After the Kernel and the Initramfs is loaded, the boot process feels quite OK in terms of speed.

Some more background:

* It's a Thinkpad X1 Carbon Gen 10 (August 2022)
* /boot is an ext4 filesystem
* LUKS for encrypted boot partition:
** Version 1
** Cipher aes
** Mode xts-plain64
** Hash sha256
** MK bits 512
** MK iterations 385505
** Key iterations 500000
* GRUB package 2.06.r297.g0c6c1aff2-1

Any ideas what could be wrong that reading from the encrypted /boot partition is so slow?

LanMarc77

Member

Registered: 2022-08-19

Posts: 12

Re: GRUB very slow loading Kernel and Initramfs from encrypted /boot

Maybe you want to join in here: https://bbs.archlinux.org/viewtopic.php?id=279006 and help us finding the problem? It seems it is the same issue.

tobru

Member

Registered: 2022-01-10

Posts: 3

Re: GRUB very slow loading Kernel and Initramfs from encrypted /boot

Yes, let's continue there, seems to be the same issue.