Filesystem problems - unable to boot

[John Dangler]

On Mon, 2006-08-07 at 09:51 -0400, Barry Tepperman wrote:
> I have become completely dependant on Ubuntu for all my personal and most of by 
> professional computing. Have successfully upgraded(except for PCMCIA wireless cards
> - another story for another time) from 5.04 - 5.10 - 6.06. After the most recent
> software update (which included a kernel upgrade to 2.6.15-26-386) now find myself
> unable to reboot. The error message IMMEDIATELY AFTER attempting to load initrd 
> in the startup sequence is "Error 16 : Inconsistent filesystem structure; press
> any key to continue....". The "press any key" gets me into the GRUB
> menu of current and previous kernels used with and without recovery mode - but none
> of them get me past the same point. I would - at the very least - like to salvage
> my data, and preferably get the system restored and running. 
> 
> So.... how to do that? 
> 
File System Consistency
File systems rely on an internal set of tables to keep track of inodes
used and available blocks. When these internal tables are not properly
synchronized with data on a disk, inconsistencies result and file
systems need to be repaired.

File systems can be inconsistent because of abrupt termination of the
operating system from the following:


      * Power failure
        
      * Accidental unplugging of the system
        
      * Turning off the system without proper shutdown procedure
        
      * A software error in the kernel
        

File system inconsistencies, while serious, are not common. When a
system is booted, a check for file system consistency is automatically
performed (with the fsck command). Often, this file system check repairs
problems it encounters.

The fsck command places files and directories that are allocated but
unreferenced in the lost+found directory. An inode number is assigned as
the name of unreferenced file and directory. If the lost+found directory
does not exist, the fsck command creates it. If there is not enough
space in the lost+found directory, the fsck command increases its size.