If you are using Kloxo and got this message:
Filesystem / (/dev/simfs) on localhost is using 91%
that mean you are using most of user space and you have free some space.
may you free your logs file like:
rm -rf var/log/exim_paniclog.[1-9].gz
rm -rf /var/log/exim_mainlog.[1-9].gz
rm -rf /var/log/exim_rejectlog.[1-9].gz
rm -rf /var/log/lfd.log.[1-9].gz
rm -rf /var/log/messages.[1-9]
rm -rf /var/log/maillog.[1-9]
rm -rf /var/log/secure.[1-9]
rm -rf /var/log/cron.[1-9]
rm -rf /var/log/rpmpkgs.[1-9]
rm -rf /var/log/boot.log.[1-9]
rm -rf /var/log/spooler[1-9]
rm -rf /var/spool/exim/input/*
rm -rf /var/spool/exim/msglog/*
rm -rf /var/cache/eaccelerator/*
rm -rf /tmp/*
rm -rf /var/tmp/*
and also logs in: /var/log/kloxo/
