Wol, et al --
...and then Wols Lists said...
%
% On 28/03/21 03:14, David T-G wrote:
% >
...
% > system is running. Soooooo ... Where do I start?
% >
% > diskfarm:~ # cat /proc/mdstat
% > Personalities : [raid6] [raid5] [raid4]
% > md0 : active raid5 sdc1[3] sdd1[4] sdb1[0]
% > 11720265216 blocks super 1.2 level 5, 512k chunk, algorithm 2 [4/3] [U_UU]
%
% This looks wrong - is this supposed to be a four-drive array? U_UU
% implies a missing drive ... as does [4/3]
Yep :-( I sent a separate note about that one.
% >
% > md127 : inactive sdl2[0](S) sdj2[3](S) sdf2[1](S)
% > 2196934199 blocks super 1.2
% >
...
% > diskfarm:~ # mdadm --examine /dev/sd[fjl]2 | egrep '/dev|Name|Role|State|Checksum|Events|UUID'
% > /dev/sdf2:
...
% > Events : 720
% > Device Role : Active device 1
% > Array State : AAA ('A' == active, '.' == missing, 'R' == replacing)
% > /dev/sdj2:
...
% > Events : 177792
% > Device Role : Active device 2
% > Array State : A.A ('A' == active, '.' == missing, 'R' == replacing)
% > /dev/sdl2:
...
% > Events : 177794
% > Device Role : Active device 0
% > Array State : A.. ('A' == active, '.' == missing, 'R' == replacing)
% >
% > Slice f2 looks great, but slices j2 & l2 seem to be missing -- even though
% > they are present. Worse, the Events counter on sdf2 is frighteningly
% > small. Where did it go?!? So maybe I consider sdf2 failed and reassemble
% > from the other two [only] and then put f2 back in?
%
% Yes I'm afraid so. I'd guess you've been running a failed raid-5 for
% ages, and because something hiccuped when you shut it down, the two good
% drives drifted apart, and now they won't start ...
Arrrgh :-( I was afraid of that ...
% >
% > Definitely time to stop, take a deep breath, and ask for help :-)
% >
% Read up about overlays on the web site, use an overlay to force-assemble
Ouch. I tried that with a hiccup a few years ago and never really got it
down. This is gonna take some reading again ...
% the two good drives, run fsck etc to check everything's good (you might
% lose a bit of data, hopefully very little), then if everything looks
% okay do it for real. Ie force-assemble the two good drives, then re-add
It looks like I want
mdadm --assemble --force /dev/md127 /dev/sd[jl]2
for that based on the Go Wrong page and Go Wrogn collection. Does that
sound right?
% the third. I'd just do a quick smartctl health check on all three drives
% first, just to make sure nothing is obviously wrong with them - a
That looks good, although perhaps quite simple:
diskfarm:~ # for D in /dev/sd[fjl] ; do echo "### $D" ; smartctl --health $D ; done
### /dev/sdf
smartctl 7.0 2019-05-21 r4917 [x86_64-linux-5.3.18-lp152.63-default] (SUSE RPM)
Copyright (C) 2002-18, Bruce Allen, Christian Franke, www.smartmontools.org
=== START OF READ SMART DATA SECTION ===
SMART overall-health self-assessment test result: PASSED
### /dev/sdj
smartctl 7.0 2019-05-21 r4917 [x86_64-linux-5.3.18-lp152.63-default] (SUSE RPM)
Copyright (C) 2002-18, Bruce Allen, Christian Franke, www.smartmontools.org
=== START OF READ SMART DATA SECTION ===
SMART overall-health self-assessment test result: PASSED
### /dev/sdl
smartctl 7.0 2019-05-21 r4917 [x86_64-linux-5.3.18-lp152.63-default] (SUSE RPM)
Copyright (C) 2002-18, Bruce Allen, Christian Franke, www.smartmontools.org
=== START OF READ SMART DATA SECTION ===
SMART overall-health self-assessment test result: PASSED
But --info is longer and still doesn't give THAT much info, so maybe this
is fine :-)
% problem could kill your array completely! Then add the third drive back
% in (whether you use --add or --re-add probably won't make much difference).
OK.
%
% Oh - and fix whatever is wrong with md0, too, before that dies on you!
Yeah, about that ... Haven't seen any replies there yet :-/
%
% Cheers,
% Wol
Thanks again & HANN
:-D
--
David T-G
See http://justpickone.org/davidtg/email/
See http://justpickone.org/davidtg/tofu.txt
