root@hinas:~# df -h
Filesystem Size Used Avail Use% Mounted on
udev 458M 0 458M 0% /dev
tmpfs 100M 15M 86M 15% /run
/dev/mmcblk1p4 5.9G 5.2G 480M 92% /
tmpfs 496M 0 496M 0% /dev/shm
tmpfs 5.0M 0 5.0M 0% /run/lock
tmpfs 496M 0 496M 0% /sys/fs/cgroup
tmpfs 496M 4.0K 496M 1% /tmp
/dev/mmcblk1p1 256M 47M 210M 19% /boot
/dev/mmcblk1p3 488M 278M 200M 59% /backupbox
/dev/mmcblk1p2 488M 413M 65M 87% /recoverybox
/dev/sda1 299G 242G 57G 82% /mnt/sda1
/dev/sdb1 3.7T 1.6T 2.1T 44% /mnt/sdb1
tmpfs 100M 0 100M 0% /run/user/0
如何清理