You can schedule cron to run a script at specific interval testing the size of a chosen directory and running your command if the size has exceeded a predefined limit, an example script is below.

#!/bin/bash



DIR=${DIR:=/home}

LIMIT=78000000



cd $DIR

SZ=$(sudo du -c|grep total|cut -f 1)



if [ "$LIMIT" -le "$SZ" ];then

  #echo "The dir is too large"

  echo 3 > /proc/sys/vm/drop_caches

fi

Depending on your chosen distro the methods for invoking cron may be different, if we has that information we could assist further,

zottelkind wrote:

can i use the Code:
also for an not Oracle Server?

Yesyou can use it for anything you want.

I posted the code for it to be public, you can use it to call to whichever command(s) you choose in cases when a size limit has been exceeded. If you are looking for a way to control quotas on users then you should check out http://www.ubuntugeek.com/how-to-setup-disk-quotas-in-ubuntu.html, that guide is for Ubuntu, if you are looking for a different distro then post it here and I can try to assist.