Re: C7, mdadm issues

Alessandro Baggi <alessandro.baggi@xxxxxxxxx> · Wed, 30 Jan 2019 14:39:26 +0100

Il 30/01/19 14:02, mark ha scritto:
On 01/30/19 03:45, Alessandro Baggi wrote:
Il 29/01/19 20:42, mark ha scritto:
Alessandro Baggi wrote:
Il 29/01/19 18:47, mark ha scritto:
Alessandro Baggi wrote:
Il 29/01/19 15:03, mark ha scritto:

I've no idea what happened, but the box I was working on last week
has a *second* bad drive. Actually, I'm starting to wonder about
that particulare hot-swap bay.

Anyway, mdadm --detail shows /dev/sdb1 remove. I've added
/dev/sdi1...
but see both /dev/sdh1 and /dev/sdi1 as spare, and have yet to find
a reliable way to make either one active.

Actually, I would have expected the linux RAID to replace a failed
one with a spare....

can you report your raid configuration like raid level and raid 
devices
and the current status from /proc/mdstat?

Well, nope. I got to the point of rebooting the system (xfs had the
RAID
volume, and wouldn't let go; I also commented out the RAID volume.

It's RAID 5, /dev/sdb *also* appears to have died. If I do
mdadm --assemble --force -v /dev/md0  /dev/sd[cefgdh]1 mdadm: 
looking for
devices for /dev/md0 mdadm: /dev/sdc1 is identified as a member of
/dev/md0, slot 0.
mdadm: /dev/sdd1 is identified as a member of /dev/md0, slot -1.
mdadm: /dev/sde1 is identified as a member of /dev/md0, slot 2.
mdadm: /dev/sdf1 is identified as a member of /dev/md0, slot 3.
mdadm: /dev/sdg1 is identified as a member of /dev/md0, slot 4.
mdadm: /dev/sdh1 is identified as a member of /dev/md0, slot -1.
mdadm: no uptodate device for slot 1 of /dev/md0
mdadm: added /dev/sde1 to /dev/md0 as 2
mdadm: added /dev/sdf1 to /dev/md0 as 3
mdadm: added /dev/sdg1 to /dev/md0 as 4
mdadm: no uptodate device for slot 5 of /dev/md0
mdadm: added /dev/sdd1 to /dev/md0 as -1
mdadm: added /dev/sdh1 to /dev/md0 as -1
mdadm: added /dev/sdc1 to /dev/md0 as 0
mdadm: /dev/md0 assembled from 4 drives and 2 spares - not enough to
start the array.

--examine shows me /dev/sdd1 and /dev/sdh1, but that both are spares.
Hi Mark,
please post the result from

cat /sys/block/md0/md/sync_action

There is none. There is no /dev/md0. mdadm refusees, saying that it's 
lost
too many drives.

       mark

_______________________________________________
CentOS mailing list
CentOS@xxxxxxxxxx
https://lists.centos.org/mailman/listinfo/centos

I suppose that your config is 5 drive and 1 spare with 1 drive failed.
It's strange that your spare was not used for resync.
Then you added a new drive but it does not start because it marks the 
new disk as spare and you have a raid5 with 4 devices and 2 spares.

First I hope that you have a backup for all your data and don't run 
some exotic command before backupping your data. If you can't backup 
your data, it's a problem.

This is at work. We have automated nightly backups, and I do offline 
backups of the backups every two weeks.

Have you tried to remove the last added device sdi1 and restart the 
raid and force to start a resync?

The thing is, it had one? two? spares when /dev/sdb1 started dying, and 
it didn't use them.

Have you tried to remove this 2 devices and re-add only the device 
that will be usefull for resync?  Maybe you can set 5 devices for your 
raid and not 6, if it works (after resync) you can add your spare 
device growing your raid set.

I tried, and that's when I lost it (again), and it refuses to 
assemble/start the RAID "not enough devices".

Reading on google many users use --zero-superblock before re-add the 
device.

I can take one out, and re-add, but I think I'm going to have to 
recreate the RAID again, and again restore from backup.

Other user reassemble the raid using --assume-clean but I don't know 
what effect it will produces

Hope that this helps.

Thanks.

     mark

Hope that someone give you a better help for this.

Update here if you got the solution.
_______________________________________________
CentOS mailing list
CentOS@xxxxxxxxxx
https://lists.centos.org/mailman/listinfo/centos