![为什么已用+可用磁盘空间总是小于总磁盘空间?](https://linux22.com/image/1266607/%E4%B8%BA%E4%BB%80%E4%B9%88%E5%B7%B2%E7%94%A8%2B%E5%8F%AF%E7%94%A8%E7%A3%81%E7%9B%98%E7%A9%BA%E9%97%B4%E6%80%BB%E6%98%AF%E5%B0%8F%E4%BA%8E%E6%80%BB%E7%A3%81%E7%9B%98%E7%A9%BA%E9%97%B4%EF%BC%9F.png)
root@localhost:~ $ df /dev/sdb1
Filesystem 1K-blocks Used Available Use% Mounted on
/dev/sdb1 1922858352 23247088 1801935664 2% /mnt/external/sdb1
已使用+可用 = 1825182752
尺寸 - 1825182752 = 97675600
答案1
97675600 / 1825182752 = 5%
这是 root 用户的默认保留空间。