Re: strange behaviour of df command

[Nigel Wade <nmw ion le ac uk>]

Atul Tyagi wrote:
> Hi All,
>
> I am facing a little problem. I guess its more of a conceptual problem
> rather than a OS issue.
>
> One of my software raid partiton /dev/md4 is about 30 GB. I had put a file
> of about 18GB in that jus for few mins and then deleted that. Now even 
> after
> about 6 hrs. My RHEL4 system gives me weird output. following are the
> outputs that might help you understand.
>
> df -h
> ===
>
> [root pingu ~]# df -h
> Filesystem            Size  Used Avail Use% Mounted on
> /dev/md0              5.0G  2.7G  2.1G  56% /
> /dev/md1               99M   17M   78M  18% /boot
> none                 1014M     0 1014M   0% /dev/shm
> /dev/md2              5.0G  190M  4.5G   4% /var
> /dev/md4               30G   22G  5.9G  79% /usr/local/test
>
> du -hs
> =====
> [root pingu ~]# du -hs /usr/local/test
> 2.7G    /usr/local/test
>
> Can some one please clear my doubt and explain why there is a such a hugh
> difference in both the commands. Disk usage shown by df -h is 22G where as
> du shows 2.7G.
>
> Would appriciate any pointer to this problem.
>
> Thanks,
>
> Atul

Is the file still open? A file which is open can have it's i-node deleted from 
the directory containing it, but the actual disk space will not be released 
until the file is closed.

Check for open file descriptors. A common cause is a large log file held open by 
syslog even after the file has been deleted.

--
Nigel Wade, System Administrator, Space Plasma Physics Group,
            University of Leicester, Leicester, LE1 7RH, UK
E-mail :    nmw ion le ac uk
Phone :     +44 (0)116 2523548, Fax : +44 (0)116 2523555