** Description changed: Symptoms: (Ubuntu 9.10 on an ext4 partition /dev/sda1) - 1. Booting fails. + 1. Booting fails with error message: + + Gave up waiting for root device. common problems + -Boot args(cat/proc/cmdline) + -check rootdelay=(did the system wait long enough?) + -check root=(did the system wait for the right device?) + Missing modules(cat/proc/modules; IS/dev) + Alert!/dev/disk/by-uuid/d3bb8e26-9798-49 ce-bc57-afb6ca6za7ba does not exist. Drop to a shell! 2. "mount /dev/sda1 /mnt" gives "mount: you must specify the filesystem type" but "mount -t ext4 /dev/sda1" is successful - 3. blkid /dev/sda1 returns nothing + 3. "blkid /dev/sda1" returns nothing - 4. blkid -p /dev/sda1 gives "ambivalent result (probably more + 4. "blkid -p /dev/sda1" gives "ambivalent result (probably more filesystems on the device)" - 5. hexdump -s 0x410 -n 2 /dev/sda1 returns on of the four numbers + 5. "hexdump -s 0x410 -n 2 /dev/sda1" returns on of the four numbers hexadecimals 137f, 138f, 2468,2478, - After installing util-linux-ng-2.17 from source: - 6. wipefs /dev/sda1 returns: + 6. "sudo BLKID_DEBUG=0xffff blkid -p /dev/sda1 | grep "minix: magic" + returns + + "ambivalent result (probably more filesystems on the device)" + minix: magic sboff=16, kboff=1 + + + 7. After installing util-linux-ng-2.17 from source: "wipefs /dev/sda1" returns: offset type ---------------------------------------------------------------- 0x410 minix [filesystem] 0x438 ext4 [filesystem] - UUID: d3bb8e26-9798-49ce-bc57-afb6ca62a7ba + UUID: d3bb8e26-9798-49ce-bc57-afb6ca62a7ba - I was able to cure the problem by creating a file on "/dev/sda1" and whereby changing the number of free inodes. There have been six of these case in the Ubuntu forums by now: + + I was able to cure the problem by creating a file on "/dev/sda1" and whereby changing the number of free inodes. + + There have been seven of these case in the Ubuntu forums by now: http://ubuntuforums.org/showthread.php?t=1397193 http://ubuntuforums.org/showthread.php?t=1414662 http://ubuntuforums.org/showthread.php?t=1068895 + http://ubuntuforums.org/showthread.php?t=1422558 + My diagnosis: Minix uses the "magic number" 137f, 138f, 2468,2478, at the location 0x410 to mark a Minix file system. 0x410 is also the location any ext filesystem uses to record the number of free inodes. - In decimals those four umbers are 4991,5007,9320,9336 + In decimals those four numbers are 4991,5007,9320,9336 If the number of free inodes happens to be one of those four numbers plus a multiple of 65536, then the ext filesystem will write one of the four Minix magic numbers to the 0x410 location. - So many programs will gets confused and don't know whether the files system is Minix or Ext. + So blkid gets confused and does not know whether the files system is Minix or Ext. In particular, if this happens on the root partition, Ubuntu will no longer boot. - Cure: Boot from the Ubuntu LiveCD and create a file on the affected - partition: + Cure: + + Boot from the Ubuntu LiveCD and create a file on the affected partition: sudo mount /dev/sda1 /mnt sudo touch /mnt/empty_file + + This solution works for an ext4 filesystem. But does not work for ext2. + For ext2 one needs to replace the UUID in fstab and grub.cfg by the + device name. See + https://sourceforge.net/apps/mediawiki/bootinfoscript/index.php?title=Boot_Problems:minix + for more details.
-- mount ext fileystem fails, booting fails, blkid produces no output https://bugs.launchpad.net/bugs/518582 You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. -- ubuntu-bugs mailing list [email protected] https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
