> Be patient...
You are likely correct as the [ext4lazyinput] process is now gone.
Probably finished up last night as the drives are quiet now.
For completeness:
> What did "cat /proc/mdstat" say?
# cat /proc/mdstat
Personalities : [raid1]
md0 : active raid1 sdc1[1] sdb1[0]
3906885440 blocks super 1.2 [2/2] [UU]
bitmap: 0/30 pages [0KB], 65536KB chunk
unused devices: <none>
Unfortunely, I can not be 100% certain if the [ext4lazyinput] process
was still active when I captured the mdstat output shown above. But
that is what it says now that the process is gone.
Thanks to everyone for their input.