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tmtvl05/04/20252 repliesview on HN

Setting GRUB up with full-disk encryption and BTRFS snapshots is braindead easy. Maybe it'd be just as easy with Gummiboot or rEFInd, but you know what they say about fixing things that aren't broken.


Replies

63stack05/04/2025

What's the current state of the art on this? Last time I looked it was really not trivial, because of two things:

1) there is only one bootloader (grub2) that can load kernels from encrypted /boot partitions, but the support for that is limited, you have to use a weaker encryption if I remember correctly, AND decryption speed (after entering the luks password) is super slow, because the CPU extensions that speed that up (AES) are not yet online that early in the boot process

2) you can choose to not encrypt /boot, and have it as a separate partition, but now your btrfs snapshots will not include the kernel, so restoring after kernel upgrades is going to break your system

show 3 replies
johnisgood05/04/2025

It really is easy, it is just mostly a matter of proper initramfs, and a "linux" line in the GRUB configuration file. Arch wiki gets into it in detail.