Upgrading NIOC to v3 – Disruptive or not?

Upgrading NIOC from version 2 to 3 is no big deal. But I’m writing this blog post because the official VMware documentation says that the upgrade to NIOC v3 is disruptive and that worried me.

We have only one dvSwitch in our virtual infrastructure and use vSAN and NSX. If this upgrade is really disruptive, we need to shut down all virtual machines before the upgrade process starts. And that would be a big deal for us and our customers.

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Understanding congestion in vSAN

If things go wrong in a VMware vSAN 6.x environment you may see congestion warnings and errors – usually in hybrid setups. I try to explain what congestion means in the world of vSAN, why it’s a problem and how to deal with it.

What is congestion?

In short, congestion occurs when you have a bottleneck in the lower layers of your vSAN infrastructure. Or, more concretely: The destaging process of the incoming data, from the flash cache to the capacity disks, is so heavy that one layer of vSAN cannot handle this amount of data.

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