[SLES 11 SP3, LVM2, lvm2-2.02]

Is there any recommendation / best practice guide on the design of volume groups:

how many should I have?

Currently we have two vgs to 6 TB each.

In the need of additional 6 TB - what are the pros and cons of creating another vg or growing the existing ones.

As the PVs are actually VMWare vdisks, the distribution of the RAID based storage is flexible with a two vg design, already.

Thanks for sharing your opinions