Name of the new RAID partition in this example: backup
Partition disk #1 (ata-YOURDISKID
/sda
in this example):
$ parted --align=optimal /dev/disk/by-id/ata-YOURDISKID
GNU Parted 3.2
Using /dev/sda
Welcome to GNU Parted! Type 'help' to view a list of commands.
(parted) mklabel gpt