[robnett]

I need some pro's and cons as to which is the best way to approach LUN creation.

[duke900ssd]

Do it on the DS and serve out whole LUNs to the clients.
There will be no overhead on the DS, as opposed to doing it on the VIOS for which there would be a performance overhead on the VIOS.
Also if there is a lun failure on the DS, only the associated client will be affected, rather then the whole system.

[ross.mather]

Do it on the DS - always.

This will allow you to use twin VIO servers later, and will prevent performance impacts due to the Logical Volume Manager in the VIO.

The reason for using DS storage in part is its big cache to speed things up. It slows the whole thing down if you use the LVM on the VIO.