LVM2 builtin raid - how to check raid status
Solution 1:
As far as I understand,
lvs -a -o name,copy_percent,devices yourvgname
will show less than 100% in the copy_percent column if your RAID devices are not in sync yet.
Solution 2:
This is old but as I am currently moving to lvm-raid my best conclusion so far is to use:
lvs -a -o name,copy_percent,health_status,devices vgroup
As this would provide %sync and health_status which I understand would be empty if all correct.