[[email protected] /]# df -h
Filesystem Size Used Avail Use% Mounted on
/dev/vda1 50G 2.2G 45G 5% /
/dev/vdb1 95G 3.9G 87G 5% /data
/dev/vdb3 796G 17G 739G 3% /opt
正常卸载：
umount /opt
报错：
[[email protected] sftp]# umount /opt/
umount: /opt: device is busy.
(In some cases useful info about processes that use
the device is found by lsof(8) or fuser(1))
强制卸载
[[email protected] ~]# fuser -cu /opt
/opt: 12954cm(root)
[[email protected] ~]# fuser -ck /opt
/opt: 12954cm
[[email protected] ~]# fuser -c /opt
[[email protected] ~]# umount /opt/
[[email protected] ~]# df -h
Filesystem Size Used Avail Use% Mounted on
/dev/vda1 50G 2.2G 45G 5% /
/dev/vdb1 95G 3.8G 87G 5% /data