按照教程里把docker的数据都放到外置里，但是overlay的分区仍然只有6.7g
Disk /dev/sda: 14.102 GiB, 16097738752 bytes, 31440896 sectors
Disk model: USB Flash Disk
Units: sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disklabel type: dos
Disk identifier: 0xa9370c04
Device Boot Start End Sectors Size Id Type
/dev/sda1 2048 3144Device Boot Start End Sectors Size Id Type
/dev/sdb1 2048 468862127 468860080 223.6G 83 Linux
root@hi3798mv100:/mnt/sda1# df -H
Filesystem Size Used Avail Use% Mounted on
/dev/root 7.1G 5.5G 1.3G 81% /
devtmpfs 489M 0 489M 0% /dev
tmpfs 489M 0 489M 0% /dev/shm
tmpfs 98M 2.3M 96M 3% /run
tmpfs 5.3M 0 5.3M 0% /run/lock
tmpfs 489M 0 489M 0% /sys/fs/cgroup
tmpfs 489M 0 489M 0% /tmp
overlay 7.1G 5.5G 1.3G 81% /mnt/sda1/docker/overlay2/8b4b619b84cddf50b51d7f42e7230adac2e5c8db450858efb86599105bdb5a1a/merged
/dev/sdb1 236G 8.0G 216G 4% /mnt/sdb1
tmpfs 98M 0 98M 0% /run/user/0
overlay 7.1G 5.5G 1.3G 81% /mnt/sda1/docker/overlay2/3409ea4e1fa461a072af014b87394111292958b298929a28f7b42c7272836364/merged
0895 31438848 15G 83 Linux
