Before enabling jumbo frames, ensure the following are true:

• The physical server's network interface card and network switch can support jumbo frames (MTU 9000)
• The switch ports of all routers and switches between SoftNAS® and VMware vSphere hosts are properly configured for MTU 9000.

VMWare ESX/ESXi supports frames up to 9 Kb (MTU 9000).

In order to use jumbo frames support configuration is required end to end.

These commands are good for ESX/ESXi 5.0 and later:

1. Log into host with the VMware vSphere client.
   
   
2. Select the physical host to make changes to and click on the host IP. 
   
   
3. Choose the Configuration tab. 
   
   
4. Select the Networking option under Hardware.
   
5. Select properties on the vSwitch to be configured. 
   When the vSwitch is selected, the MTU set will become visible under Advanced.
   
6. Set Properties. The default is 1500. 
   
   
7. Click Edit on the bottom while the vSwitch is selected. 
   
   
8. On the Generaltab there is a box labeled Advanced Properties
   
9. Change the MTU here from 1500 to 9000 and click OK.
   
10. Also change the MTU for the VMK (VM kernel). 
    In the same vSwitch Properties box select the first VMK listed. 
    
    
11. The MAC address and MTU are listed under NIC Settings. 
    
    
12. Click Edit for the first VMK.
    
    
13. On the properties dialogue box that pops up set the MTU in the NIC settings box on the General tab to 9000 and click OK.
    
    
14. Repeat this for all VMKs under the virtual switch.
    
    
15. Close the vSwitch properties dialogue and repeat for any remaining vSwitches. 

Be sure to set the SoftNAS® network interface to accept Jumbo Frames / MTU 9000, as described above.