vSAN over ONLY 2NICs?

Mareo · Wed Oct 02, 2024 11:28 am

Hello all,

I honestly don't know how to even search for this and I hope I will ask this right. I know I made a thread awhile back, but I would like to keep this separate.

Is it possible to create a vSAN HA Cluster Failovering and all that jazz using only two NICs? On a recent project I have created a cluster using Starwind and we have four NICs. HB1 and HB2 with Sync1 and Sync2.

However, we have two nodes that cannot be upgraded with additional NICs and we are thus doomed to only two of them, which would be made of HB1 and Sync1.

So, is it possible or even at all recommended to create Cluster Failovering using only two NICs or is four the way to go, no matter what? And to immediately follow up with another question, if I would go about that - what are the changes? Does the setup remain the same and I go about creating all that without using additional NICs?

Thanks in advance and kind regards,
Mario

Wed Oct 02, 2024 11:53 am

Is it possible to create a vSAN HA Cluster Failovering and all that jazz using only two NICs?

Yes. Make sure that the redundancy requirement is met https://www.starwindsoftware.com/system-requirements.
See the script for many IPs here viewtopic.php?f=5&t=6852&p=37208.
If Switches are used for iSCSI and SYNC traffic, make sure they are redundant too.

However, we have two nodes that cannot be upgraded with additional NICs and we are thus doomed to only two of them, which would be made of HB1 and Sync1.

That's still not a problem. You can replicate via SYNC1 on one node and SYNC1 on another.
It is better to get them on the separate networks.
And, no traffic mixing, plese.

And to immediately follow up with another question, if I would go about that - what are the changes? Does the setup remain the same and I go about creating all that without using additional NICs?

The approach is always the same, no matter how many NICs you use. The only thing is please make sure that the redundancy requirement is met.
Here is a small trick that I do. I draw the setup and all interconnects. I ask myself if crossing a single component will completely interrupt comms between nodes on the StarWind level. Then, I cross the links, NICs, Switches, and inter-site comms one by one, seeing if there ever is a situation there is no at least one backup link there.

P.S. StarWind VSAN provides the HA storage. Clustering magic is done by the Hypervisor.