Partition information!!!

[Govind C]

Folks,
I have SUN "SS3315" attached to Linux Box running Redhat3.0 UP5.I had 
created a logical drive of 750GB and mapped the LUN to linux box.

[root at console root]# fdisk /dev/sdc

Disk /dev/sdc: 749.3 GB, 749347012608 bytes
255 heads, 63 sectors/track, 91102 cylinders
Units = cylinders of 16065 * 512 = 8225280 bytes

   Device Boot    Start       End    Blocks   Id  System
/dev/sdc1             1     91102 731776783+  83  Linux

[root at console root]# df -k
/dev/sdc1            288378940 214279140  59450932  79% /san

Why is it that /dev/sdc1 shows only 290GB when the total size is 
750GB.Am I missing out any configuration?