for dd

core@ip-172-16-32-92 ~ $ docker exec -it zookeeper bash
root@ip-172-16-32-92:/opt/zookeeper# df -h  
Filesystem      Size  Used Avail Use% Mounted on
overlay          74G  4.1G   66G   6% /
tmpfs           7.4G     0  7.4G   0% /dev
shm              64M     0   64M   0% /dev/shm
tmpfs           7.4G     0  7.4G   0% /sys/fs/cgroup
/dev/xvda9      5.5G  405M  4.8G   8% /tmp/zookeeper
/dev/md0         74G  4.1G   66G   6% /etc/hosts
tmpfs           7.4G     0  7.4G   0% /proc/kcore
tmpfs           7.4G     0  7.4G   0% /proc/latency_stats
tmpfs           7.4G     0  7.4G   0% /proc/timer_stats
root@ip-172-16-32-92:/opt/zookeeper# exit