Bad size of disk

Hi,

I have VM with 500GB thin prov. size. It is Centos6 server.

From DF I have:

[root@beta ~]# df -h
Filesystem            Size  Used Avail Use% Mounted on
/dev/mapper/vg_beta-LogVol00
                       20G  2.5G   16G  14% /
tmpfs                 7.8G     0  7.8G   0% /dev/shm
/dev/sda1             5.8G  253M  5.3G   5% /boot
/dev/mapper/vg_beta-LogVol01
                       49G  2.1G   44G   5% /var
/dev/mapper/vg_beta-LogVol02
                      418G  6.2G  390G   2% /www

So it is about 10GB used space on disk.

But in vCenter - VM - Performance - Storage is Virtual Disk 322GB used.  (Storage browser this too)

Any help? Thank you

Pavel