report file system disk space usage
Filesystem Size Used Avail Use% Mounted on
-h
-h, –human-readable
print sizes in powers of 1024 (e.g., 1023M)
df -h
–max-depth
-a, –all
include pseudo, duplicate, inaccessible file systems
du -ah --max-depth=1 <目录，缺省为当前目录>
单独列出<目录路径>各一级子项占用的容量
-s
du -sh <目录，缺省为当前目录>
查看<目录路径>总共占的容量（而不单独列出各子项占用的容量）
-T
print file system type
Filesystem Type 1K-blocks Used Available Use% Mounted on
