du会把指定目录下所有文件、目录、目录下的文件都统计。是建立在文件系统能看到的的确确是有这样一些文件的基础上的。也就是说我们能在文件系统里面看到的文件才会被du统计。
df命令可以获取硬盘被占用了多少空间，目前还剩下多少空间等信息，它也可以显示所有文件系统对i节点和磁盘块的使用情况。
常用操作
# du -h --max-depth=1
18G ./caomall_bak_2018_1120
17G ./caomall
35G .
# du -h --max-depth=2
80M ./caomall_bak_2018_1120/installed
16M ./caomall_bak_2018_1120/logs
20K ./caomall_bak_2018_1120/pids
100K ./caomall_bak_2018_1120/seahub-data
247M ./caomall_bak_2018_1120/seafile-pro-server-6.2.9
168K ./caomall_bak_2018_1120/ccnet
28K ./caomall_bak_2018_1120/conf
17G ./caomall_bak_2018_1120/seafile-data
4.4M ./caomall_bak_2018_1120/pro-data
18G ./caomall_bak_2018_1120
80M ./caomall/installed
16M ./caomall/logs
20K ./caomall/pids
100K ./caomall/seahub-data
247M ./caomall/seafile-pro-server-6.2.9
176K ./caomall/ccnet
28K ./caomall/conf
17G ./caomall/seafile-data
4.4M ./caomall/pro-data
17G ./caomall
35G .
# du -h --max-depth=2 /opt/caomall
80M /opt/caomall/installed
16M /opt/caomall/logs
20K /opt/caomall/pids
32K /opt/caomall/seahub-data/avatars
64K /opt/caomall/seahub-data/thumbnail
100K /opt/caomall/seahub-data
47M /opt/caomall/seafile-pro-server-6.2.9/seafile
708K /opt/caomall/seafile-pro-server-6.2.9/upgrade
852K /opt/caomall/seafile-pro-server-6.2.9/seahub-extra
98M /opt/caomall/seafile-pro-server-6.2.9/seahub
68M /opt/caomall/seafile-pro-server-6.2.9/pro
132K /opt/caomall/seafile-pro-server-6.2.9/create-db
34M /opt/caomall/seafile-pro-server-6.2.9/runtime
247M /opt/caomall/seafile-pro-server-6.2.9
16K /opt/caomall/ccnet/OrgMgr
12K /opt/caomall/ccnet/misc
36K /opt/caomall/ccnet/GroupMgr
100K /opt/caomall/ccnet/PeerMgr
176K /opt/caomall/ccnet
28K /opt/caomall/conf
8.0K /opt/caomall/seafile-data/httptemp
4.0K /opt/caomall/seafile-data/tmpfiles
17G /opt/caomall/seafile-data/storage
300K /opt/caomall/seafile-data/library-template
4.0K /opt/caomall/seafile-data/commits
4.0K /opt/caomall/seafile-data/fs
17G /opt/caomall/seafile-data
204K /opt/caomall/pro-data/search
4.4M /opt/caomall/pro-data
17G /opt/caomall
# df -h
文件系统 容量 已用 可用 已用% 挂载点
/dev/vda1 99G 41G 53G 44% /
devtmpfs 3.9G 0 3.9G 0% /dev
tmpfs 3.9G 0 3.9G 0% /dev/shm
tmpfs 3.9G 460K 3.9G 1% /run
tmpfs 3.9G 0 3.9G 0% /sys/fs/cgroup
tmpfs 783M 0 783M 0% /run/user/0
# du -h ./seahub.db
1.5M ./seahub.db
小结：想统计全部的可以使用
df -h想统计具体文件夹或者文件的，可以使用
du -h --max-depth=1默认是所有，可以指定深度，1或者2就够了
可以查看根目录的使用情况
# du -h --max-depth=1 /