The EFAX had me worried a moment, but these are 12TB Reds? That's fine.
A lot of the smaller drives are now shingled, ie not fit for purpose!
Debian 10 - I don't know my Debians - how up to date is that? Is it a
new kernel with not much backports, or an old kernel full of backports?
What version of mdadm?
That said, everything looks good. There are known problems - WITH FIXES
- growing a raid 5 so I suspect you've fallen foul of one. I'd sort out
a rescue disk that you can boot off as you might need it. Once we know a
bit more the fix is almost certainly a rescue disk and resume the
reshape, or a revert-reshape and then reshaping from a rescue disk. At
which point, you'll get your array back with everything intact.
yes, that´s the 12TB WD-Red - I´m using five pieces of it.
The Debian 10 is the most recent one. Kernel version is 4.9.0-12-amd64.
mdadm-version is v3.4 from 28th Jan 2016 - seems to be the latest,
because I can´t upgrade to any newer one using apt upgrade.
I don´t think I need a rescue disk, because the raid isn´t bootable.
It´s simply a big storage.
Thanks a lot for your support.
