On Mon, Apr 14, 2014 at 7:34 PM, John D. Baker jdba...@mylinuxisp.com wrote:
I had occasion to deal with a system whose hardware RAID-5 had lost a
component and operated in degraded mode for some time. Following a
power failure, the machine (a DELL PowerEdge 2550, IIRC) refused to boot
from the degraded, but operational RAID.
The failed component was replaced and the RAID card's firmware utility
was used to reconstruct the logical volume. The machine then proceeded
to boot, but the filesystem check revealed very damaged filesystems.
Fortunately, the owner of the system had practiced good separation of
infrastructure vs application. I ultimately declared the OS filesystems
a total loss and installed a fresh 6.1_STABLE from sometime in the
middle of 2013 (and recently updated, then updated to i386-6.99.40).
The remaining filesystem is where the user's data resides. From my
previous attempts at salvaging the OS filesystems, I can expect more
orphaned files than can be referenced in a single lost+found directory.
From a brief perusal of fsck_ffs sourcecode, it appears that if the
linkup() routine returns 0 (zero) for any reason, the inode being
processed is simply cleared.
I'd like to give the best possible chance to recover data but I don't
really feel like having to approve 65534 reconnections. I'd like to use
the -y option, but have fsck exit if it can't attach the orphan file.
Then I can move the lost+found directory out of the way and start over
with a new one.
That seem reasonable?
Sorry to go off topic a bit.
What is your goal? To recover newer stuff than the owner was able to
get back? In this case you probably need to go through every inode I
guess. What's it worth? At some point it becomes harder than the data
is worth... You probably know that.
I assume when you say routine returns 0 means it can't link the
inode and it just removes it? Sorry, I didn't look at the code...
If you're not using -y, I guess you would have to script your way
through using -n and moving the bad stuff out of the way every time
you hit it, unless you have a better idea. I'd like to hear it.
Andy
