10 Dec
2018
10 Dec
'18
6:47 a.m.
Commands line options:
rd.debug rd.udev.debug systems.log_level=debug
That willl be incredibly verbose, and slows things down a lot, so in the off chance there's a race, you might get different results. But if not, the log should contain something useful.
I like the hypothesis about mdadm metadata version 0.9, however that's still really common on RHEL and CentOS. It was used for /boot prior to about Fedora around Fedora 24 maybe?
At least I didn't have any problems on my systems having all metadata version 1.2, which seems the default for CentOS 7.
Maybe it's a good idea to upgrade those arrays with older metadata before doing the 7.6 upgrade.
Regards, Simon