Since a few months my /usr partition got full every end of the month. I reset the logs for some few very active domains manually. e.g.:

/scripts/runweblogs dhb
/scripts/runweblogs dhb
rm -f
rm -f
touch -f
../bin/apachectl graceful

I execute /scripts/runweblogs twice such that I do not loose to much of the stats if the runweblogs runs too long.

But for the last weeks I could delete the logs all the time and the partition got full though.

At the moment, the domlogs directory is 61MB. /usr is 7.7GB.
The strange thing is:
df reports 87% full - so only 1GB free. Same does phpSysInfo and CPanel always notifies me when the free disc space drops further.

But when I use du to see which directories use all the space it only reports 2.5 GB of used space! I read that df is not comparable to du. But how can I find out where the missing 3.5 GB are lost.

May there be a problem with the file system? Is './apachectl graceful' not enough?