Hi ,
Please read this post before the question

the answer in that port says
2 NICs work as Vswitch will power up the ISCSI access.

and I have seen there are lots of dual port or quad port network adatpter,
what if I use a quad port network adapter for ISCSI access , will it have the almost same result as I use 4 NICs to work as vSwitch?

asked 07/06/2011 01:17

GordonLiq's gravatar image

GordonLiq ♦♦

4 Answers:
It does not matter if it is 4 seperate NIC's or a single 4 port NIC, if that is your question? The effect will be the same.

As you see in the example picture I posted in that thread, I actually use 2 four port NIC's in each physical server, so 8 physical ports. I use two cards from different manufacturers, for added redundancy and if a VSwitch needs just 2 ports then I use one from each card. etc...
Neilsr's gravatar image


Can you point some document or link to supply your side?
GordonLiq's gravatar image


I know of no technical paper that points to such a conclusion, either for or against. I can only talk from experience.
Personally I would always favor multiple physical NIC's rather that a Single NIC purely for hardware redundancy.  If you have a single 4 port NIC and that fails, your in the sticky stuff! However IF you have two dual port NIC's then the chance of total failure is halved.
As for performance it makes very little or no difference at all.
As was shown on my example in the other question, using 2 cards allows you to create a virtual Switch that has ports on multiple physical adaptors, reducing the risk of failure. Should one NIC card fail, the switch still has access to a port on the other NIC.
Neilsr's gravatar image


The only way to attach multiple physical NICs to a vSwitch in Hyper-V is to team them. The proper way to do it with iSCSI is to have a separate virtual network for each NIC, attach each virtual network to the VM, and use MPIO from the VM to the SAN storage.

The servers I buy now come with 4 network ports on the motherboard (Dell). I buy dual port NICs if I need more because the cost per port is low, and I can add or remove ports in pairs instead of quads, which is more flexible.
kevinhsieh's gravatar image


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Asked: 07/06/2011 01:17

Seen: 547 times

Last updated: 07/19/2011 10:11