Bug#542425: error: cannot find a device for /.

[Albin Stjerna]

At Fri, 28 Aug 2009 12:57:53 +0200,
Felix Zielcke wrote:
> If you'd have that problem then there should be /dev/dm-0 or something
> like that instead of the /dev/mapper name.
> Anyway your / is encrypted and grub2 doestn't support that yet.

My / is encrypted, but GRUB 2 is loading some initramfs I think, which in turn
decrypts it. It’s all auto-configured, so I’m not really sure, but it’s using LUKS.

> Well make sure that /boot/grub/unicode.pf2 exists, if not then copy it
> from /usr/share/grub

It’s there.

> Else run `sh -x grub-mkconfig', maybe that tells why it wants to
> access /
> If not then you have to add `x' to the `#!/bin/sh -e' line in
> every /etc/grub.d/ file and run again grub-mkconfig.

The output’s a bit over my head, but a point of interest seems to be:

+ set /usr/sbin/grub-mkdevicemap dummy
+ test -f /usr/sbin/grub-mkdevicemap
+ :
+ set /usr/sbin/grub-probe dummy
+ test -f /usr/sbin/grub-probe
+ :
+ mkdir -p /boot/grub
+ test -e /boot/grub/device.map
+ :
++ /usr/sbin/grub-probe --target=device /
grub-probe: error: cannot find a device for /.

Apparently, for some reason it’s running grub-probe on /, which, of course,
isn’t registered with GRUB. The only partition it’s supposed to know about is my
(unencrypted, plain) boot partition (/dev/hda1). Now, what I’m wondering is why
GRUB has forgotten this: I haven’t touched any of GRUB’s settings!