device free space limit setting

[komtanoo.pinpimai at livetext.com]

Hi,

I had set up mogilefs in a very bad practice -- 1 partition holding
everything(OS + devX). I have many of these machines which will take
sometime to migrate. Now, one of them is filled up by mogilefs:

colo3:/tmp# df -h
Filesystem            Size  Used Avail Use% Mounted on
/dev/sda3             228G  217G     0 100% /

It's not totally out of space, but df shows 100% and it makes me worry.

Is there any parameter I can set to prevent this, like setting a device to
readonly if available space is less than 20G or 90% ?