I agree with all off the comments above. For iSCSI, almost every iSCSI vendor requires that each iSCSI vmkernel (i.e. iSCSI1 and iSCSI2) are using different physical uplinks, so you would make vmnic0 as "Active" and vmnic1 as "Unused" for iSCSI1 and vice-versa for iSCSI2. However, for most other port groups, (i.e. Management, NFS, VM Traffic) most designs I've seen use Active/Active uplinks with Virtual Port ID load balancing (or Load-Based Teaming on Distributed vSwitch). The design simulator on DCD seems to be pushing us to configure Active/Standby everywhere which is certainly valid but not as common as Active/Active and Active/Unused is correct for iSCSI. Active/Standby would be correct for Multi-NIC vMotion but I don't think they want us to plan for multi-NIC vMotion.
Agreed on the NFS vs. iSCSI questions. Almost always the NFS traffic is on a separate vmkernel from iSCSI, since iSCSI typically involves two vmkernels, often on separate subnets, for MPIO to work correctly. NFS is typically on a single subnet with Active/Active uplinks using NIC failover rather than MPIO.
Another problem I recall from the exam is that the simulations always call for "Dual HBAs" or "Dual 10 Gig NICs", but it is unclear whether they want a single PCI card with dual ports, or two actual PCI cards. The graphics in the simulator appear as though each PCI card has dual ports, and adding a 2nd PCI card usually is too "busy" for the Visio, i.e. there often is not enough space to hold two PCI cards. So to me, a single PCI card with two ports seems to be what they are asking. But another common design is two physical PCI cards to protect against a PCI card failure brining down the whole vSwitch...
Another question is Jumbo Frames. Technically Jumbo Frames are optional for iSCSI. Some people use them, many people do not. Each iSCSI vendor has different recommendations. The scenario doesn't specifically tell us to use jumbo frames, but it allows us to configure it. Since it is optional, what is the right answer?
I would love to know what goes on inside the "Black Box" that calculates partial credit for these mock design simulations... in other words if we design port groups with Active/Active links, which is perfectly normal and reasonable, do we get docked points because the exam author wanted Active/Standby?
Bill Oyler
Systems Engineer
