Bug#542435: grub-probe: error: cannot find a device for /. (LVM2)

[Felix Zielcke]

Am Mittwoch, den 19.08.2009, 18:12 +0200 schrieb Stefan
Lippers-Hollmann:
> Package: grub-common
> Version: 1.96+20090808-1
> Severity: important
> 
> Hi
> 
> Since 2.02.51-1 (17 Aug 2009), lvm2 depends on dmsetup, which ships a few 
> udev rules:
> 
> /lib/udev/rules.d/55-dm.rules
> /lib/udev/rules.d/60-persistent-storage-dm.rules
> /lib/udev/rules.d/95-dm-notify.rules
> 
> Trying to call grub-probe (indirectly through grub-install or update-grub)
> on a kernel whose initramfs includes these udev rules results in grub-probe
> failing to find the / "partition" (a logical volume on LVM2):
> 
> # grub-probe  --target=device /
> grub-probe: error: cannot find a device for /.
> 
> This failure breaks installing grub2 on a pure LVM2 system and renders an 
> installed system (which has always been working fine for me) on LVM2 
> unbootable, as soon as dmsetup and its udev rules enter the initramfs and 
> when update-grub gets invoked by installing kernel updates.
> 
> Deleting dmsetup's udev rules and regenerating the initramfs makes 
> grub-probe working again.
> 
> I am reliably experiencing this problem, which renders the affectable 
> systems unbootable on initramfs changes or kernel updates, on 3 systems 
> using ext3 and ext4 for / since dmsetup got pulled in by lvm2. It is 
> independent of the installed kernel version (2.6.29 - 2.6.31-rc6-git5)
> Please feel free to reassign to dmsetup (lvm2), but I assume grub-probe 
> simply can't interpret the mangled udev representation since dmsetup got 
> installed.
> 

Are the /dev/mapper/* files still created or are there now just
the /dev/vg/lv ones?
grub-probe only supports the /dev/mapper/ ones.