https://access.redhat.com/solutions/1609793
fdisk /dev/sdc ---- Create partition similar to root disk also mark boot disk label.
mkfs.xfs /dev/sdc1 --- make boot disk.
mount /dev/sdc1 /mnt
cp -a /boot/* /mnt/
grub2-install --boot-directory=/mnt /dev/sdc
Update /etc/fstab
blkid /dev/sdc1
Reboot the system.
grub2-mkconfig -o /boot/grub2/grub.cfg
Extend VG
vgextend systemvg /dev/sdc2
move LV one by one
pvmove -b -n rootlv /dev/sda2 /dev/sdc2
Monitor the progress
lvs -a -o+devices