# before forcing question



## ivand58 (Jun 19, 2010)

Hi,

the problem is 

```
# umount /data
umount: unmount of /data failed: Device busy
```

And here is the question: how to find out who keeps this device busy ?

Or is there another way to find what will happen if I use "-f" to unmount the device?


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## nekoexmachina (Jun 19, 2010)

> how to find out who keeps this device busy ?


sysutils/lsof, sysutils/fuser


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## DutchDaemon (Jun 19, 2010)

fstat(1) (no need for lsof)


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## mk (Jun 20, 2010)

you can just type  *pwd* to see where are you. common mistake for me - umount usb while in dir where is mounted (dull)


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## ivand58 (Jun 24, 2010)

`# fstat /data`
gives empty line

```
USER     CMD          PID   FD MOUNT      INUM MODE         SZ|DV R/W NAME
```

but:
`# fstat -v /data`
returns

```
...
unknown file type 5 for file 13 of pid 1128
can't read vnode at 0x0 for pid 45
can't read vnode at 0x0 for pid 44
...
```

and do this mean that i have to kill all these processes to unlock the mounted device?


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