It seems the bug is that dmraid -i -r -cr /dev/sda is listing the name of the first subset rather than the superset. Your workaround won't work if you have more than one array so it seems the underlying bug will need to be fixed to have raid10 work.
It seems the bug is that dmraid -i -r -cr /dev/sda is listing the name of the first subset rather than the superset. Your workaround won't work if you have more than one array so it seems the underlying bug will need to be fixed to have raid10 work.