From a fresh Rocky Linux install, need to add some repos.
# dnf install epel-release -y
https://docs.rockylinux.org/books/lxd_server/01-install/
Install the repo instructions for getting zfs
dnf install https://zfsonlinux.org/epel/zfs-release-2-2$(rpm --eval "%{dist}").noarch.rpm
Installing zfs pulls in all the kernel modding requirements like kernel-devel and gcc
dnf install zfs
Load the zfs module
/sbin/modprobe zfs
Add some disks (use lsblk to see what's attached) in a pool (see zfs docs to decide with raid to use)
zpool create datapool mirror /dev/sdb /dev/sdc
or
zpool create datapool raidz /dev/sdb /dev/sdc
Put a filesystem called data on it:
zfs create datapool/data