discrepancies in disk usage between df and du

[Paul Schmehl]

You have a file locking problem.  du shows disk in use, but df shows disk 
committed.  Use lsof to identify the file that has disk space reserved but 
no longer exists.  man (8) lsof

--On February 12, 2010 5:39:44 PM -0300 Fernan Aguero 
<fernan.aguero at gmail.com> wrote:

> Hi,
>
> I have a box (7.2-STABLE, amd64) that is currently showing some disk
> usage problems. It all started with apache generating huge logs from
> one of the mod_perl applications that is undergoing testing. So the
> /var partition was getting full.
>
> We removed all logs that were causing the problem, but even though du
> shows some 700 Mb of usage, df shows that the disk is full (-1.5 Gb):
>
> [fernan at omega ~] sudo du -hc -d1 /var/
> Password:
> 2.0K	/var/.snap
> 423M	/var/account
> 6.0K	/var/at
> 2.0K	/var/audit
>  18K	/var/backups
> 4.0K	/var/crash
> 6.0K	/var/cron
>  53M	/var/db
> 2.0K	/var/empty
> 2.0K	/var/heimdal
> 219M	/var/log
>  14M	/var/mail
> 4.0K	/var/msgs
>  48K	/var/named
> 2.0K	/var/preserve
>  44K	/var/run
> 2.0K	/var/rwho
>  16K	/var/spool
>  76K	/var/tmp
>  24K	/var/yp
> 2.0K	/var/games
> 710M	/var/
> 710M	total
>
> [fernan at omega ~] df -h
> Filesystem                Size    Used   Avail Capacity  Mounted on
> /dev/mirror/gm0s1f         18G     18G   -1.5G   109%    /var
>
> I've been googling around, and I understand why df and du might be
> reporting disk usage differently. However, I can't solve this issue
> and reclaim unused disk space ... applications (apache, mod_perl) are
> prevented to write to /var and this is causing us problems.
>
> We've already tried rebooting the box, restarting the syslog,
> newsyslog daemons, to no avail. df keeps showing >100% disk usage
> (-1.5 Gb of remaining disk space) in all cases. We've even rebooted
> the box with all apache instances turned off in rc.conf ... i.e.
> without any but the most basic services running (sshd) ...
>
> This box is essentially a web server, no other services are being run.
>
> Any suggestions as to what to try next?
>
> Thanks in advance,



Paul Schmehl, If it isn't already
obvious, my opinions are my own
and not those of my employer.
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