Hi,
It's all in the documentation from Red Hat.
kickstart snip https://access.redhat.com/documentation/en-US/Red_Hat_Enterprise_Linux/7/htm...
manual partitionning https://access.redhat.com/documentation/en-US/Red_Hat_Enterprise_Linux/7/htm... scroll down to 6.14.4.2. Create Software RAID
ymmv,
Tru