my df coimmand output after installed FC3.

[Wong Kwok-hon <kwokhon@xxxxxxxxx>]

Filesystem            Size  Used Avail Use% Mounted on
/dev/mapper/VolGroup00-LogVol00
                            18G  3.2G   14G  19% /
/dev/hda1              99M  8.8M   85M  10% /boot
none                     252M     0  252M   0% /dev/shm

Do my system using LVM2 ? And all data is in a same harddisk only.
Is it conventient in add one more hard disk ?

Thanks!