[CentOS] Kickstart file for software raid

I am using a kickstart file for CentOS 7

raid /                                      --device=md0 --fstype="xfs"
--level=1 --useexisting
raid /home     --noformat       --device=md1
 --level=1 --useexisting

It is erroring out on the --useexisting.

The exact text is:
RAID volume "0" specified with "--useexisting" does not exist.

What did I do wrong?

Jerry