[root@server1] fdisk -l 
Disk /dev/hda: 80.0 GB, 80026361856 bytes
255 heads, 63 sectors/track, 9729 cylinders
Units = cylinders of 16065 * 512 = 8225280 bytes

   Device Boot      Start         End      Blocks   Id  System
/dev/hda1   *           1          13      104391   83  Linux
/dev/hda2              14        1216     9663097+  8e  Linux LVM

<snip>

[root@server1 ~]# lvextend -L+40G /dev/VolGroup00/LogVol01
  Extending logical volume LogVol01 to 40.75 GB
  Insufficient free space: 1280 extents needed, but only 1 available