i am using redhat 9
Linux version 2.4.20-8smp (bhcompile@porky.devel.redhat.com) (gcc version 3.2.2 20030222 (Red Hat Linux 3.2.2-5))

At some points when issuing df -h it shows disk usage 100 % even there is more than 12 Gb is free .So at that some of applications failing.

Disk space retained only after rebooting.

Could you please provide some solution to get the disk sapce at run time.