pvcreate /dev/sda2
pvcreate /dev/sdb5
vgcreate vg /dev/sda2 /dev/sdb5
lvcreate -n data -L 390g vg /dev/sdb5
lvcreate -n cache -L 100g vg /dev/sda2
lvcreate -n meta -L 1g vg /dev/sda2
lvconvert --type cache-pool --poolmetadata vg/meta vg/cache
lvconvert --type cache --cachepool vg/cache --cachemode writeback vg/data