On your NetApp filer you can easily configure multiple VLANs with differing MTU on the same LACP trunked 1GbE or 10GbE ports with stacked IPs on the storage VLAN network to assist with load balancing.  In this example, network 10.0.0/24 (VLAN 10, MTU 1500) is just the regular network. Network 10.0.1/24 (VLAN 20, MTU 9000) is the NFS storage network. On your switch create an LACP trunk to the filer's interfaces and then trunk VLANs 10 and 20. Your ESXi servers storage network would also be on VLAN 20 and use the load balancing policy of Route based on IP hash. On the switch you would create a static trunk (since ESXi 5 does not support LACP). The VMkernel port on the vSwitch would be untagged for the storage network.

Here's /etc/rc:

hostname filer1
ifconfig e0a flowcontrol send
ifconfig e0b flowcontrol send
ifconfig e0c flowcontrol send
ifconfig e0d flowcontrol send
vif create lacp NETWORK -b ip e0a e0b e0c e0d
vlan create NETWORK 10 20
ifconfig NETWORK-10 `hostname`-NETWORK-10 netmask mtusize 1500 -wins partner
ifconfig NETWORK-20 `hostname`-NETWORK-20 netmask mtusize 9000 -wins partner
ifconfig NETWORK-20 alias `hostname`-NETWORK-20-ALIAS-1 netmask
ifconfig NETWORK-20 alias `hostname`-NETWORK-20-ALIAS-2 netmask
ifconfig NETWORK-20 alias `hostname`-NETWORK-20-ALIAS-3 netmask
route add default
routed on
options dns.enable on
options nis.enable off

Ensure /etc/hosts is populated correctly with the IP of both toasters in the event of failover/failback: localhost filer1 filer1-NETWORK-10 filer1-NETWORK-20 filer1-NETWORK-20-ALIAS-1 filer1-NETWORK-20-ALIAS-2 filer1-NETWORK-20-ALIAS-3 filer2 filer2-NETWORK-10 filer2-NETWORK-20 filer2-NETWORK-20-ALIAS-1 filer2-NETWORK-20-ALIAS-2 filer2-NETWORK-20-ALIAS-3

Ensure your VM exports (/etc/exports) are secured ensuring only access from your ESXi VMKernel port on the storage switch of each ESXi host - in this case there are 3 ESXi hosts. Additionally, individual IPs don't necessarily need to be used if an entire subnet requires rw and root access to the VM volumes:

/vol/root      -sec=sys,rw,anon=0,nosuid
/vol/root/home -sec=sys,rw,nosuid
/vol/downloads -sec=sys,rw,nosuid
/vol/vm00      -sec=sys,rw=,root=
/vol/vm01      -sec=sys,rw=,root=
/vol/vm02      -sec=sys,rw=,root=
/vol/vm03      -sec=sys,rw=,root=
/vol/iso       -sec=sys,rw=,root=

This configuration would be need to be made identically on filer1 and filer2 with the exception that on filer2 the hostname changes in /etc/rc.