[CentOS] Drive failed in 4-drive md RAID 10

Sat Sep 19 23:16:51 UTC 2020
Kenneth Porter <shiva at sewingwitch.com>

--On Friday, September 18, 2020 10:53 PM +0200 Simon Matter 
<simon.matter at invoca.ch> wrote:

> mdadm --remove /dev/md127 /dev/sdf1
> and then the same with --add should hotremove and add dev device again.
> If it rebuilds fine it may again work for a long time.

This worked like a charm. When I added it back, it told me it was 
"re-adding" the drive, so it recognized the drive I'd just removed. I 
checked /proc/mdstat and it showed rebuilding. It took about 90 minutes to 
finish and is now running fine.