Re: VFS: Cannot open root device

On Fri, 2025-09-05 at 11:15 +0000, Cliff mcDiarmid wrote:
> Hello
> 
> I've never had any issue so far recompiling the kernel for LFS.   Still
> there's always a first.
> 
> After enabling some modules in an existing kernel(6.12.5) I get the following
> error when rebooting:
> 
> VFS: Cannot open root device
> "/dev/nvme0n1p4" or unknown block (0,0): error -6
> Please append a correct "root=" boot option
> List of of all bdev filesystems  etc etc

Here the lines you replaced with "etc etc" are important, look at them
carefully.  We enabled DRM panic and VESA framebuffer in LFS
specifically to make the kernel able to show them clearly on such a
"cannot open root device."

Possibilities are you incorrectly changed CONFIG_EXT4 to M, incorrectly
changed CONFIG_NVME to M, incorrectly turned off CONFIG_EFI_PARTITION,
or you have two NVME disks and their numbering changed between two
boots.

-- 
Xi Ruoyao <[email protected]>

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