umount: device is busy

问题： umount命令遇到报错： umount: /usr/test01: device is busy.

解决：可以使用fuser的-m选项看一哪些进程在占用，在允许的情况下，将进程杀掉，就可以umount了。

示例：

testenv:~ # df -h

Filesystem                    Size  Used Avail Use% Mounted on

/dev/mapper/rootvg-lv01        50G   46G  943M  99% /

...

/dev/mapper/rootvg-lv000001   25G   22G  1.5G  94% /db2data

/dev/mapper/rootvg-vm          30G  7.3G   21G  26% /vm

/dev/mapper/rootvg-lv00002     15G  166M   14G   2% /usr/test01
/dev/mapper/testvg01-lv0003    15G  166M   14G   2% /usr/test01

testenv:~ # umount /dev/mapper/testvg01-lv0003
umount: /usr/test01: device is busy.

        (In some cases useful info about processes that use

         the device is found by lsof(8) or fuser(1))

You have new mail in /var/mail/root

testenv:~ # umount -f /dev/mapper/testvg01-lv0003

umount2: Device or resource busy

umount: /usr/test01: device is busy.

        (In some cases useful info about processes that use

         the device is found by lsof(8) or fuser(1))

umount2: Device or resource busy

testenv:~ #
fuser -m /usr/test01

/usr/test01:           5777

testenv:~ # ps -ef | grep -i 5777

root      5777     1  0 Jan10 ?        00:01:26 /usr/test01/myprogrm/bin/mydisco

root      8395  5580  0 09:56 pts/0    00:00:00 grep -i 5777

testenv:~ # kill 5777

testenv:~ # umount /dev/mapper/testvg01-lv0003

testenv:~ # df -h

Filesystem                    Size  Used Avail Use% Mounted on

/dev/mapper/rootvg-lv01        50G   46G  943M  99% /

...

/dev/mapper/rootvg-lv000001   25G   22G  1.5G  94% /db2data

/dev/mapper/rootvg-vm          30G  7.3G   21G  26% /vm

/dev/mapper/rootvg-lv00002    9.9G  1.2G  8.2G  13% /usr/test01