Re: RAID5 failure and consequent ext4 problems

[David T-G <davidtg-robot@justpickone.org>]

Phil & Luigi, et al --

...and then Phil Turmel said...
% 
...

% 
% You haven't mentioned whether your --create operations specified
% --assume-clean.

He hasn't?


% 
% On 9/9/22 17:01, Luigi Fabio wrote:
...
% > 
% > On Fri, Sep 9, 2022 at 4:32 PM Luigi Fabio <luigi.fabio@gmail.com> wrote:
% > > 
...
% > > > But I'll be brutally honest:  your data is likely toast.
% > > Well, let's hope it isn't. All mdadm commands were -o and
% > > --assume-clean, so in theory the only thing which HAS been written are
% > > the md blocks, unless I am mistaken and/or I read the docs
% > > incorrectly?
...
% > > This is the list of --create and --assemble commands from the 6th
...
% > >   9813  mdadm --assemble /dev/md123 missing
% > >   9814  mdadm --assemble /dev/md123 missing /dev/sdf1 /dev/sdg1
...
% > >   9815  mdadm --assemble /dev/md123 /dev/sdf1 /dev/sdg1 /dev/sdk1
...
% > > /dev/sdm1
% > >   9823  mdadm --create -o -n 12 -l 5 /dev/md124 missing /dev/sde1
...
% > >   9824  mdadm --create -o -n 12 -l 5 /dev/md124 missing /dev/sde1
...
% > >   9852  mdadm --create -o --assume-clean -n 12 -l 5 --metadata=0.90
...
% > >   9863  mdadm --create -o --assume-clean -n 12 -l 5 --metadata=0.90
...
% > >   9879  mdadm --create -o --assume-clean -n 12 -l 5 --metadata=0.90
...
% > >   9889  mdadm --create -o --assume-clean -n 12 -l 5 --metadata=0.90
...
% > >   9892  mdadm --create -o --assume-clean -n 12 -l 5 --metadata=0.90
...
% > >   9895  mdadm --create -o --assume-clean -n 12 -l 5 --metadata=0.90
...
% > >   9901  mdadm --assemble /dev/md123 /dev/sdn1 /dev/sde1 /dev/sdf1
...
% > >   9903  mdadm --create -o --assume-clean -n 12 -l 5 --metadata=0.90
...
% > > 
% > > Note that they all were -o, therefore if I am not mistaken no parity
% > > data was written anywhere. Note further the fact that the first two
% > > were the 'mistake' ones, which did NOT have --assume-clean (but with
% > > -o this shouldn't make a difference AFAIK) and most importantly the
% > > metadata was the 1.2 default AND they were the wrong array in the
% > > first place.
[snip]

I certainly don't know what I'm talking about, so this is all I'll say,
but it looked reasonably complete to me ...


HTH & HANW

:-D
-- 
David T-G
See http://justpickone.org/davidtg/email/
See http://justpickone.org/davidtg/tofu.txt