50 gig slash went from 25 gig to 50 gigs- full over night

[Jim Christiansen]

Hello,  My server system has gone from its slash drive being  50% full to 
100% over night-

[root at christiansens ~]# df -h
Filesystem            Size  Used Avail Use% Mounted on
/dev/sda1              48G   48G     0 100% /

I've looked at the size of every directory in slash and they all add up to 
about 25 gigs or so...
/home is on another partition.

Where did all of the space go to in /dev/sda1??

I did rename a mount point in fstab to a new name and made a dir in slash to 
mount it to but I'm sure that this didn't have anything to do with my 
current trouble.  The system did restart several times since the rename to 
the new mount point with out any issure...  Then this morning...  slash is 
100% full.

I run this as an ltsp server based on FC5 and none of my clients will boot 
with slash being 100% full.

Ideas??

Thanks,  Jim