On Wed, Oct 18 2017, sfunk1x wrote:

On 10/18/2017 12:40 PM, Wols Lists wrote:

quoted

What does --detail tell us about the array?

https://imgur.com/a/Own0W

Apologies for the imgur link, but this was the easiest way to
communicate --detail.

Anything is better than nothing..  Can we get a photo of "mdadm
--examine" output on one of the devices (e.g. /dev/sda1) ??

Also, what mdadm version (mdadm -V) and kernel version (uname -r)?

quoted

Are you sure the three drives were added? SELinux has a habit of causing
havoc. Did the available space on the array increase? Did you check?

Yeah. The array took about 17 hours to rebuild with the three drives
added (I had expected over 24 as that had been my experience with adding
the 5th drive long ago), and I had immediately started using the extra
space. The extra 8+ TB showed up in --details, as well as df, and my
guests could see the extra space.

The SELinux audit log, however, was very clear about mdadm not being
able to edit the conf. And it's true - the conf file did not have the
extra drives added. I've since audited and applied a rule to allow the
editing of the conf file, but the system is currently in permissive mode
until the array is back online. I can disable if needed.

mdadm never tries to edit mdadm.conf.
It does modify files in /run/mdadm (or maybe /var/run/mdadm).
Can we get a photo of that audit log?

I'm very suspicious of these new drives appearing to have not metadata.
Can you
   od -x /dev/sdf | head
   od -x /dev/sdf | grep a92b
and provide a photo of the output?

NeilBrown