Extending root partition

Hello!

Im new to Turnkey Linux, but have been very impressed with the virtual appliances so far! I have downloaded and am currently using the lamp, mysql and torrent appliances and think they are very good and well set up! However, the issue i am facing is the virtual hdd that the appliances come with are only 20GB and these are just too small. So, i was trying to make them bigger by using LVM comands, but these didnt work, here is the output:

root@lamp ~# lvextend -L+230G /dev/turnkey/root
  Extending logical volume root to 247.00 GiB
  Insufficient free space: 58880 extents needed, but only 165 available
 

I made sure that there was enough space on the hdd by setting the size to 255GB within VMWare ESXi and this showed as i booted a live cd of ubuntu and the extra space showed in the disk manager.

Any help is much appreciated!

Cheers! =)