dvswitch traffic shaping ingress/egress when to turn it on

hi all,

i have link aggregiate compatible (vsphere 5.0), lacp vsphere 5.1 and hp 4500-g2 10G nic on a jumbo frame enable on a cisco 3750x. when do i need to enable traffic shaping?  why the default ave/peak bandwidth is  100meg/s and burst size is 102meg bytes?

if i have 10G nic on my ip san (but 1Gx2 link aggregiate on dvswitch ip san port group), how should i set my average/peak bandwidth and burst size?  also on my dvswitch vm port group, if have 4 nic link aggregiate on it, what bandwidth and burst size should i use?

thanks for any comment you may add.