/dev/root does not exist: USB with Fedora Workstation (via Fedora Media Writer) has problems booting without CSM

I have written the newest offical version of Fedora Workstation on an USB via Fedora Media Writer, when trying to boot into it without CSM I am getting the following error:

Warning: /dev/disk/by-label/Fedora-WS-Live-39-1-5 does not exist
Warning: /dev/root does not exist

On my old motherboard turning on CSM and then booting into it with the new option works, but on my new motherboard (B650-Plus Wifi) I have trouble getting CSM to work, so I am currently not able to boot and install fedora via my usb stick.

So I am looking for a way to boot into fedora without using CSM.

Edit: Thank you for your suggestions, sadly when trying again I was just getting black screens, but I now managed to fix the issue which prevented me from turning CSM on and installed it that way.


for context this is how the partitions on the stick look

Does it drop you to a recuse shell after showing that warning? If so, what does ls -al /dev/disk/by-label show? If it is just a problem with udev finding the label, you might be able to adjust the root= kernel parameter to point to one of the other aliases for the device (e.g. something like root=live:/dev/sdc3).

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I would disconnect all usb devices except the one being used to boot.
I also would use the bios boot menu to select that device specifically marked as uefi for booting (or set the bios to use only uefi mode for booting).

It may be that the system is getting confused by having more than one usb device attached since only the bios is active up to the point that it starts to load the OS.

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@boonboonboon

Please,
when posting updates post them as a new comment in order in the thread

Editing an earlier post makes it difficult or impossible to follow a timeline on when that comment was made or what it applies to.

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Thank you for the advice I will keep it in mind for the next time

how you solved it can you explain it ?? i am facing the same issue

If I remember correctly the OS Type had to be set to other OS rather than windows in order for CSM to be enabled which is weird since on my old pc (also asus mainboard) that was not the case. I still think that the point of the Fedora Media Writer is that the usb just works without having to configure anything, so it would be interesting to find out why it doesn’t in our cases.

The fedora 39 install usb is a hybrid device which means it is capable of booting in either MBR mode or UEFI mode. If bios is set to boot uefi only then the device automatically boots in uefi mode. If set to CSM mode then the user must select either MBR or UEFI at the time of booting using the bios boot menu.

I note that /dev/root does not exist for me on any of my UEFI booted systems so I would not expect that it does exist on any systems that are installed for UEFI boot mode.

I just checked an MBR booting VM with F39 and /dev/root also does not exist there.

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/dev/root only exists during the later stages of the initramfs. Earlier stages find, decrypt, etc. whatever root is set to on the command line. Once whatever root is set to is available, a symlink named /dev/root is created that points to it. Then, in the “mount” stage, /dev/root is mounted to /sysroot, then the “switch root” phase starts. After the switch root phase, /dev/root is no longer visible.

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