1 pNIC DP 10Gb/s or 2 pNIC for vSAN Node?

[lolo31]

Hello,

As we can see on Storage and Availability Technical Documents , single pNIC DP 10Gb/s are often used.

Ok, it's enough to manage all the traffic (and NIOC is very helpfull in this situation)

OK, it's cheaper, less cable, less 10Gb/s port used on pSW, etc.

But what about SPOF with a single DP 10Gb/s on each node?

What do you think ?

1x pNIC and we don t care about pNIC spof.

or No, you need redondancy at every level and pNIC is one of them.

Thanks

Regards.

LS

[TheBobkin · Accepted solution]

Hello lolo31,

Having network redundancy is always a benefit - whether it's worth the additional cost/upkeep etc. depends entirely on your set-up and whether you consider it necessary and worth having in this implementation.

There are numerous references to using redundant NICs in the current vSAN networking guide and outlines of typical configurations:

storagehub.vmware.com/export_to_pdf/vmware-r-vsan-tm-network-design

Bob

[GreatWhiteTec]

Hi LS,

A design Best Practice will call for no SPOF, so ideally you would have 2+ pnics. One common design is to have vSAN on pNIC1 as active and pNIC2 as passive, other traffic can use pNIC2 as active and pNIC1 as passive. On top of that use NIOC so that in the event of port failure, vSAN can have preference when all traffic is on a single port. Since you mentioned DP 10Gb card, then this would become your SPOF. So it is a matter of what you can afford vs. your redundancy desires/SLAs, etc.

Hope that helps

[lolo31]

Ok so,

The point is, you need to understand what does that involve to get only one pNIC Dual Port 10Gb/s instead of 2 in term of high availibilty.

Explain this to the customer and he can choose what he wants with SLA and $ in mind.

That make sense, Thanks for your advices TheBobkin and GreatWhiteTec !

Regards.

LS

[TheBobkin]

Hello lolo31

Yes, it may seem a bit overly simplistic but I feel that it really does come down to 'how much do you want/need it'.

The existing environment does also factor into this though, e.g. if the cluster is only connected to a single switch then dual NICs isn't going to eliminate network links as SPOF, and thus a common set-up is active/standby with two NICs each going to different switches.

Another factor is maintenance - if only connected to a single switch then network maintenance may require downtime, vSAN is designed as a flexible solution with the ability to do maintenance on nodes without VMs ever having downtime so this kind of negates this.

Bob

[Stanley_]

I would say.. it depends on..

- how many nodes do you have in VSAN cluster?

- what is your HW support contract? 4h mission critical  or next bussiness day?

- how critical are the VM's on this VSAN?

    this is not a full list of questions.. 

for example:

if you have just 2-4 nodes i will go with two separate NIC

if you have more nodes in cluster pNIC DP should be fine

but always it depends on answers from questions above