blocks to-bcache /dev/my_vg/my_lv

make-bcache --block 4k --bucket 2M -C /dev/sdc4

bcache-super-show /dev/sdc4 | grep cset.uuid
echo 'above_uuid' > /sys/block/bcache0/bcache/attach

# cat /sys/block/bcache0/bcache/state
no cache

# bcache-super-show /dev/my_vg/my_lv | grep cache_state
dev.data.cache_state    0 [detached]

make-bcache -C /dev/sdc4

echo 'uuid' > /sys/block/bcache0/bcache/attach

make-bcache --block 4k --bucket 2M -C /dev/nvme0n1p1

make-bcache --bucket 2M -C /dev/nvme0n1p1