umount 提示 device is busy 解决方法

想umount一个不用的磁盘，结果提示:

[root@qttc mydata]# umount /mydata     
umount: /mydata: device is busy.
        (In some cases useful info about processes that use
         the device is found by lsof(8) or fuser(1))

于是只好用fuser命令来查看磁盘占用情况:

[root@qttc mydata]# fuser -m -v /mydata
                     USER        PID ACCESS COMMAND
/mydata:             root      16016 ..c.. bash
                     root      25011 ..c.. bash

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