错误提示

root@debian:~# umount /dev/vdb1
umount: /mnt: target is busy
        (In some cases useful info about processes that
         use the device is found by lsof(8) or fuser(1).)

解决方式

方法一：lsof

#使用lsof查看占用
root@debian:~# lsof /mnt/
COMMAND   PID USER   FD   TYPE DEVICE SIZE/OFF    NODE NAME
cloudreve 428 root  cwd    DIR 254,17     4096 1048577 /mnt/cloudreve
cloudreve 428 root  txt    REG 254,17 40524232 1048579 /mnt/cloudreve/cloudreve

#使用kill解除占用
kill -9 428

方法二：fuser

#安装fuser
apt install psmisc 
#查看在使用的进程
root@debian:~# fuser -mv /mnt/
                     USER        PID ACCESS COMMAND
/mnt:                root     kernel mount /mnt
                     root        428 ..ce. cloudreve
#使用kill解除占用
kill -9 428