setup a new vlan interface on cisco nexus

You need to create your L2 VLAN first

vlan 80
name DB

Create the L3 VLAN interface

interface Vlan80
  description ## Layer 3 DB VLAN ##
  no shutdown
  no ip redirects
  ip address 172.100.0.250/24
  ip router eigrp 100
  no ip passive-interface eigrp 100
  hsrp 80
    authentication text SomePW
    preempt
    priority 120
    ip 172.100.0.254

Add the new VLAN to the trunk

Make sure to add it not replace or you'll take everything down

interface port-channel10

  description ### PortChannel vPC Peer-Link DO NOT CHANGE ##

  switchport mode trunk

  switchport trunk allowed vlan 1,10,52,60,70-71,80,172,2200

  spanning-tree port type network

  vpc peer-link

Assign the vlan to the ports

interface Ethernet101/1/33

  switchport access vlan 80

  spanning-tree port type edge

copy run start

GW on hosts should be 172.100.0.254

If you want to make a DMZ interface you don't create the L3 interface, just the L2 VLAN and assign the ports. Your default route should be out to the ASA.