vsan_vds_overview

Sometimes I just have to do it. And that’s GEEK-OUT. Over the weekend I’ve feasted on geek-out. And guess what? It’s alive!! My VSAN is alive……!

This was my weekend check list:

tasklist

Although not needed as VSAN has been around for a while now, I wanted to upgrade my lab to the latest vSphere version. And I must say, upgrading my 6.0 vSphere environment to 6.5 was seamless. In particular, I really liked the 2 stage approach in upgrading vCenter. VMware continues to make software defined infrastructure easy. Great job guys….

So, I can confirm it my VSAN is alive and kicking. And I love it. But in this blog I’ll not talk so much about VSAN, instead I’ll talk about networking. And networking is key to VSAN. So think networks first.

As with all other vSphere clustered services, VSAN relies on high-speed, inter-node connectivity. Although it’s tempting to jump straight in, my advice is first carefully plan your network. I decided to use a dedicated VLAN with 2 x dedicated ports per each host. Now as this is hyper-converged, all network traffic including VSAN will go through the same IP switches. There’s no separate storage fibre channel switching here, I’ll use the same IP switch for VMs and VSAN traffic. So, it’s important to segregate VSAN traffic to ensure best performance.

On my Cisco managed switch I configured 6 ports to be used for my VSAN VLAN. Of course in production you’d use a stack of at least 2 x IP switches to ensure resilience, but hey this is my lab. Now when configuring my VLAN these are the settings I used:

VLAN Id2
Dedicated subnet10.208.218.1/28
Jumbo framesEnabled
MulticastEnabled

With the physical IP switch configured I set about configuring the required vSphere virtual switch. Although not strictly required, my design decision was to create a vSphere Distributed Switch (VDS). But as I said, my objective is hands-on for the learning opportunity. Shown above you’ll see the dedicated VDS created for VSAN.

Now my network runs VSAN dedicated traffic. In my next blogs I’ll talk about how each server node had a disk group added to VSAN. And how these disk groups got joined over the network to make up the single datastore presented to each ESXi host. Then over this network how VSAN storage objects are distributed.

What have I learnt?

  • Network planning is key. Do this first
  • Best to use dedicated VLAN if using same switches for all network traffic
  • Ensure resiliency by using multiple ports per hosts. And at least 2 x IP switches in your stack
  • Enable multicast and Jumbo frames on your switch
  • Document VSAN network for future reference and trouble shooting

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