linux查看文件夹，文件的大小
du -h 文件夹
示例
[search@QT-H-0124 mysql]$ du -h data
1.7M    data/opendata_test
212K    data/performance_schema
4.0K    data/test
1020K   data/mysql
49G     data


df -h
示例
[search@QT-H-0124 mysql]$ df -h
Filesystem            Size  Used Avail Use% Mounted on
/dev/mapper/VolGroup00-lv_root
                      197G  7.2G  180G   4% /
tmpfs                  16G   16K   16G   1% /dev/shm
/dev/mapper/VolGroup00-lv_application
                      686G  7.5G  644G   2% /application
/dev/sda2            1008M   55M  902M   6% /boot
/dev/sda1            1022M   23M 1000M   3% /boot/efi
/dev/mapper/VolGroup01-lv_data0
                      916G  316G  554G  37% /data0