`df -k` is not updating the right space status without reboot
I have a linux systems with RHEL-4 installed with seven partitions, SATA Harddisk size is 160GB , My /usr becomes 95%, When I checked using `df -k` , SoI deleted Some logs from there and freed Space upto 35 GB, Now when I give `df -k`. Its Still showing the old space status. How do I get the right status from `df -k` without rebooting thet system.
I tried by giving sync, and even remounted that by giving foll command
mount -o remount /usr
Still , Its showing the old status, but When I check using
`du -sh` , it shows the right status, Why `df -k` is not giving the right status