SOLVED - Re: GRUB and encrypted /boot

[Volker Wysk]

Hi

I've solved this by using the Ubuntu Desktop 25.10 Installer. It isn't in
the 24.04 installer. There, you need to chose "Delete harddisk and install
Ubuntu". Then it lists several possibilities about how to do that. You need
to chose "encrpyt with a passphrase using ZFS." (All translated back from
German)

This sets up two ZFS datasets (=file systems), for /boot and for /. This
means that you have two file systems again, which could lead to
inconsistencies with the other when rolling one of them back. But this is
anticipated. ZFS has provisions for always snapshotting/rolling back in
sync. 

In other words: What I tried to do with Btrfs works with ZFS now.

Cheers,
Volker


Am Donnerstag, dem 05.02.2026 um 10:56 +0100 schrieb Volker Wysk:
> Hi.
> 
> Is it true, that GRUB can nowadays handle fully encrypted mass storage,
> which includes the /boot partition? And that this can be set up with the
> Ubuntu Server Installer?
> 
> ChatGPT told me that, and I browsed around a bit, which seemed to conferm
> it.
> 
> The thing is, I want Btrfs, which provides the snapshot feature. This is
> really cool, but won't work when /boot is in a partition separate from /. 
> 
> I've set up the partitions with the Ubuntu Server Installer, several
> times,
> tried Ubuntu Server 24.04 and 25.10, and I think I did it right. But later
> in the process I get this message (translated back from German):
> 
> "Sorry, a problem occured when finishing the installation." (very
> meaningful...)
> 
> In the log, this appears:
> 
> "grub-install: error: attempt to install to encrypted disk without
> cryptodisk enabled. Set 'GRUB_ENABLE_CRYPTODISK=y' in file
> '/etc/default/grub'."
> 
> Are there any chances to make this work?
> 
> TIA,
> Volker