Re: Dracut fails to boot root-fs

On 11/04/26 at 12:49, Michael wrote:
>On Saturday, 11 April 2026 00:49:56 British Summer Time Carsten Hauck
>wrote:
>> Dear list,
>> Gentoo has been my distribution of choice for more than 20 years, I
>> borked my systems more than once but always found a solution
>> eventually. Not so now.
>> Some time ago I aquired a refurbished Gen. 3 HP ZBook as a replacement
>> for my Very Old Laptop. I installed Gentoo following the handbook and
>> the relevant wikipages covering LVM and encryption of the root
>> filesystem. It failed to boot. As I couldn't figure out what I had
>> done wrong I installed Devuan to be sure not to have a hardware
>> issue. That booted perfectly fine. So I did a complete reinstall on
>> the partitions left over from Devuan. An efi-partition, a
>> boot-partition and a big LUKS-encryptet partition with a swap and a
>> root vg.
>> Again, I could not boot the root fs.
>> After meddling for a while without success I figured, that I am just
>> too dumb for LVM and that my thread model allows for unencryptet
>> swap. Again I did a complete reinstall after repartitioning, this
>> time without using LVM.  The problem persists.
>>
>> The installation went smoothly and the chroot works as expected. I use
>> GRUB as bootmanager and sys-kernel/gentoo-kernel-bin to rule out
>> configuration issues. GRUB loads the kernel without problem and I am
>> prompted for the luksOpen passphrase. After entering the correct
>> passphrase nothing happens for several minutes until I am dropped
>> into a dracut rescue shell.
>> It states:
>> dracut Warning: Could not boot.
>> dracut Warning: /dev/disk/by-uuid/73afXXX does not exist
>
>Did you install 'sys-fs/cryptsetup' before creating the initramfs with
>dracut?
>
>What modules have you added in /etc/dracut.conf?

Hi Michael, thanks for the answer.
Yes, cryptsetup is installed and it obviously works. After dropping to 
the shell I can mount and access /dev/mapper/cryptroot without any 
further actions requiered.
The modules I expect to need are all included by default, so at the 
moment I have no further modules added. I wonder if udev should scan the 
decrypted LUKS-device again? 

>
>> I can mount and access the root filesystem (/dev/mapper/cryptroot)
>> without problem but even after mounting it on /sysroot and exiting the
>> shell it fails to boot and drops me right back into the shell.
>>
>> dracut:/# blkid
>> /dev/nvme0n1p3: UUID="66b9XXX" TYPE="swap" PARTUUID="7f17XXX"
>> /dev/nvme0n1p1: UUID="C900XXX" BLOCK_SIZE="512" TYPE="vfat"
>> PARTUUID="9f76XXX"
>> /dev/nvme0n1p4: UUID="332dXXX" TYPE="crypto_LUKS" PARTUUID="52a0XXX"
>> /dev/nvme0n1p2: LABEL:"boot" UUID="aef0XXX" BLOCK_SIZE="4096"
>> TYPE="ext2" PARTUUID="c457XXX"
>> /dev/mapper/cryptroot: LABEL="root" UUID"73afXXX" BLOCK_SIZE="512"
>> TYPE="xfs"
>>
>> dracut:/# cat /proc/cmdline
>> BOOT_IMAGE=/vmlinuz-6.18.18-gentoo-dist root=UUID=73afXXX ro
>> rd.lang=de rd.vconsole.keymap=de-latin1
>> rd.luks.name=332dXXX=cryptroot
>>
>> I tried to modifie the GRUB commandline to access the root filesystem
>> by LABEL or by /dev/mapper/cryptroot with the same effect.
>> Everything seems to work: GRUB, the initramfs, cryptsetup... so I
>> don't have an idea what's going wrong. Only thing is, there is no
>> entry for /dev/mapper/crypt
>
>I think you meant to write: "/dev/mapper/cryptroot"

My bad, of course I meant the device that is also adressed by 
"/dev/mapper/cryptroot"

>> in /dev/disk/by-uuid and in
>> /dev/disk/by-label.
>>
>> Anyone pointing me to the Obvious and Stupid mistake I'm making (or
>> giving me other meaningfull advice) would be greatly appreciated.
>>
>> Kind regards
>>
>> Carsten
>