[long] major problems on fs; e2fsck running out of memory

[Keith Keller]

On Sun, Jun 01, 2014 at 11:24:51PM -0400, Theodore Ts'o wrote:
> 
> The "get root inode failed" is rather unfortunate.

Heh, I like your understatement.  :)  I think this helps answer part of
my questions in my second email: I should probably try to preserve
changes from last backup before getting too deep into a tricky e2fsck.
At one point the fs was still mountable, so I could have tried to copy
files off first.  (In a physical failure scenario it's exactly what I'd
have done, but I wasn't thinking of that in this case.)

> Try running "debugfs /dev/dm0"
> 
> and then use the "stat /" command.

No happiness:

# ./e2fsprogs-1.42.10/debugfs/debugfs /dev/dm-0
debugfs 1.42.10 (18-May-2014)
debugfs:  stat /
stat: A block group is missing an inode table while reading inode 2

My hunch is that it would take a large and lucky effort to try to get
anything useful off this fs.  Does that seem like a reasonable guess?

--keith

-- 
kkeller at wombat.san-francisco.ca.us