I am not sure, about that though, because suppose I need to create another VG(volume group) or change the existing extents of the already created volume group then I have to add more Physical Volumes..I dont think so....I understand I can change the VG details, but suppose I need to divide up an existing VG which was already created into a LV, I think you should be able to Volume groups from Logical Volumes..
as I stated the below commands work, and they are precisely the reason why one would need to create another VG with different extents from a LV thats there.I am just not sure why I dont see anything on the internet about creating volume groups from logical volumes.
vgcreate -s 2300 newVG /dev/mapper/existing_LV
lvcreate -l 40 -n better_LV newVG
ALSO:a very important is that you can create(Lv) logical volumes from other (LV)logical volumes, you dont only create (LV)logical volumes from (VG)volume groups only.Unless it is initial..PV added to VG then VG added to the LV.
Last edited by cbtshare; 03-19-2013 at 10:18 PM.