Because the goal of creating the initrd is to use an EVMS volume as your root file system, you also need to update the fstab file. Edit /etc/fstab with a text editor. There should be an entry in the file similar to the following:
/dev/evms/RootVolume / ext2 defaults 1 1
Replace RootVolume with the actual name of your root volume, and ext2 with the appropriate type for the root file system.