Public bug reported: Upgraded from Karmic to Lucid with root=UUID=xxxx set in grub and using UUID in /etc/fstab. System fails to boot because the root device cannot be found. >From busybox shell determined /dev/disk/by-uuid missing. Note behaviour is identical with grub and grub2 Further investigation suggests problem is with udev and initramfs interaction.
udev's 60-persistent-storage.rules amongst others contains the line KERNEL!="sr*", IMPORT{program}="/sbin/blkid -o udev -p $tempnode" with an explicit path for blkid This is used to populate udev's db which the rule ENV{ID_FS_USAGE}=="filesystem|other|crypto", ENV{ID_FS_UUID_ENC}=="?*", SYMLINK+="disk/by-uuid/$env{ID_FS_UUID_ENC}" uses to create the /dev/disk/by-uuid links, However initramfs (in the file /usr/share/initramfs-tools/hooks/udev) copies /sbin/blkid from the host system to /lib/udev in the initramfs image. The net result is that it appears (at least from the busybox environment) that blkid cannot be found and hence does not run. Several other posts (ubuntu forums) suggest various workarounds (e.g. going back to /dev/sda1 type root= lines in grub) but this is purely masking the problem not solving it. All other program references in udev (eg.ata_id usb_id and I guess the old vol_id that preceded blkid) did not have an explicit path. Replacing the references to /sbin/blkid to simple blkid in udev rules and recreating initramfs via update-initramfs -u appears to fix the problem and the system boots OK. However I am concerned that there may be other reasons why the /sbin reference was included and hence if this was introduced as a patch may break some other aspect I am unaware of. Current environment: udev 151-12 kernel 2.6.32-22-generic initramfs-tools 0.93.2~bpo50+2 initramfs-tools-bin 0.92bubuntu78 distro Ubuntu 10.04 LTS grub-pc 1.98-1ubuntu6 ** Affects: ubuntu Importance: Undecided Status: New -- After upgrade to Lucid /dev/disk/by-uuid missing when booting with initramfs https://bugs.launchpad.net/bugs/576071 You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs