[CentOS] Help setting up USB drive

I have my 640GB USB drive connected to a CentOS 5 server and using
fdisk, it seems to show a partition of the correct size, /dev/sdd1, but
after mounting, the drive shows only 244M size. Does the message
received when running fdisk below mean I should reformat this drive, I
can't seemed to figure out how to do that with fdisk. Can someone tell
me how to reformat, if needed? The drive is empty, I formatted a while
back on a Debian machine....

[root at vhost1 ~]# /sbin/fdisk /dev/sdd

The number of cylinders for this disk is set to 77825.
There is nothing wrong with that, but this is larger than 1024,
and could in certain setups cause problems with:
1) software that runs at boot time (e.g., old versions of LILO)
2) booting and partitioning software from other OSs
   (e.g., DOS FDISK, OS/2 FDISK)

Command (m for help): p

Disk /dev/sdd: 640.1 GB, 640135028736 bytes
255 heads, 63 sectors/track, 77825 cylinders
Units = cylinders of 16065 * 512 = 8225280 bytes

   Device Boot      Start         End      Blocks   Id  System
/dev/sdd1               1       77825   625129281   83  Linux

Command (m for help): q

[root at vhost1 ~]# mount -t ext3 /dev/sdd1 /home/usb
[root at vhost1 ~]# df -h|grep usb
/dev/sdd1             244M  6.1M  225M   3% /home/usb
[root at vhost1 ~]# ls -lah /home/usb
total 21K
drwxr-xr-x 3 root root 1.0K May 10 14:38 .
drwxr-xr-x 8 root root 4.0K May  9 23:26 ..
drwx------ 2 root root  12K May 10 14:38 lost+found
[root at vhost1 ~]# du -d 1 -h /home/usb
du: invalid option -- d
Try `du --help' for more information.
[root at vhost1 ~]# du -h /home/usb
12K	/home/usb/lost+found
13K	/home/usb

-- 
Robert

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--> http://saintcolumbus.livejournal.com