linux - Merge LVM Partition with unallocated Space

I have a linux hard drive with three areas:

• /dev/hda1 - ext3 boot partition (20 MB)


• /dev/hda2 - lvm2 main partition (6 GB)


• unpartitioned space - 12 GB

I would like to merge the unpartitioned space into the lvm2 partition known as /dev/hda2. I tried using GParted, but it does not support lvm2.

What commands or utilities could I use to add the unpartitioned space to hda2 without losing my existing data?