Hi,
I'm trying to unmount a file system, but it keeps saying its busy.

sparrow / # umount /downloads
umount: /downloads busy

but I've tried looking with fuser and lsof to find an open file, but
can't find one.

sparrow / # umount /downloads
umount: /downloads busy
sparrow / # fuser /downloads
/downloads:
sparrow / # lsof +d /downloads
sparrow / # umount /downloads
umount: /downloads busy

In the end I forced the unmount with the -f argument to umount, but
I'd like to know why it was happening in the first place.



--
Dr. David Kirkby,
Senior Research Fellow,
Department of Medical Physics,
University College London,
11-20 Capper St, London, WC1E 6JA.
Website: http://www.medphys.ucl.ac.uk/~davek
Author of 'atlc' http://atlc.sourceforge.net/

>> On Tue, 09 Sep 2003 19:11:45 +0100,
>> "Dr. David Kirkby" <drkirkby@ntlworld.com> said:

> Hi, I'm trying to unmount a file system, but it keeps
> saying its busy.

> sparrow / # umount /downloads umount: /downloads busy

> but I've tried looking with fuser and lsof to find an
> open file, but can't find one.

> sparrow / # umount /downloads umount: /downloads busy
> sparrow / # fuser /downloads /downloads: sparrow / #
> lsof +d /downloads sparrow / # umount /downloads umount:
> /downloads busy

> In the end I forced the unmount with the -f argument to
> umount, but I'd like to know why it was happening in the
> first place.

is it exported through NFS?

Maybe

# share

shows it exported?

hth
t

Tony Curtis wrote:
>
> >> On Tue, 09 Sep 2003 19:11:45 +0100,
> >> "Dr. David Kirkby" <drkirkby@ntlworld.com> said:
>
> > Hi, I'm trying to unmount a file system, but it keeps
> > saying its busy.
>
> > sparrow / # umount /downloads umount: /downloads busy
>
> > but I've tried looking with fuser and lsof to find an
> > open file, but can't find one.
>
> > sparrow / # umount /downloads umount: /downloads busy
> > sparrow / # fuser /downloads /downloads: sparrow / #
> > lsof +d /downloads sparrow / # umount /downloads umount:
> > /downloads busy
>
> > In the end I forced the unmount with the -f argument to
> > umount, but I'd like to know why it was happening in the
> > first place.
>
> is it exported through NFS?
>
> Maybe
>
> # share
>
> shows it exported?
>
> hth
> t


Thanks, that was the reason. I'm surprised I did not think of it. None
of the machines which mount the file system were on, so I don't think I
would have done any harm forcing the unmount.


--
David Kirkby Ph.D

Dr. David Kirkby wrote:

> Thanks, that was the reason. I'm surprised I did not think of it. None
> of the machines which mount the file system were on, so I don't think I
> would have done any harm forcing the unmount.
>

NFS can be a strange one at times... I remember once having a filesystem
that would not umount. I eventually traced it down to being held by a
<defunct> process that used to be an nfsd. Unfortunately it was on
Solaris 8, so I didn't have the luxury of preap ( Solaris 9 Rocks!

Ian Fitchet wrote:
> Beardy <beardy@beardy.net> writes:
>
>
>>Dr. David Kirkby wrote:
>>
>>
>>>Thanks, that was the reason. I'm surprised I did not think of it. None
>>>of the machines which mount the file system were on, so I don't think I
>>>would have done any harm forcing the unmount.
>>
>>NFS can be a strange one at times... I remember once having a
>>filesystem that would not umount. I eventually traced it down to being
>>held by a <defunct> process that used to be an nfsd. Unfortunately it
>>was on Solaris 8, so I didn't have the luxury of preap ( Solaris 9
>>Rocks!
>
>
> Funnily, I think it was on Solaris 8 there was a neat side effect of
> the /usr/proc/bin commands. I had a similar problem with strangely
> defunct processes (though nothing so annoying as holding a filesystem
> up) and discovered that pmap would cause a defunct process, parented
> by init, to finally exit.

Cool :-)

> Of course, the first time it happened: "bugger, fancy init reaping
> the process just then, I was trying to debug it."
>
> Cheers,
>
> Ian

Warmer ;-}

I had a nasty attack of newbie-ism once, wherein I couldn't mount a
filesystem manually, but if I rmdir'd the mountpoint, and mkdir'd it
with the same name, the filesystem would mount fine.

Took me a while to figure out that it was bcoz the mountpoint was NFS
shared (even though it was empty), and thus I couldn't mount a
filesystem on top of it.

DOH!