There is no dedicated storage network needed with Nutanix as AHV leverages the data network as the backplane for storage. In AHV based deployments, CVM, Hypervisor and Guest VMs connect with physical network via Open vSwitch (OVS). 

An instance of OVS is present on each AHV host and all instances of OVS in a cluster forms a single logical switch (somewhat similar to VMware vDS concept).

In a default AHV installation, all the interfaces present in the NX node are grouped together in a single bond called bro-up. A typical NX node ships with 2×10 GB and 2×1 GB interface. 

The following diagram illustrates the networking configuration of a single host immediately after imaging.

Although the above configuration works just fine in most of the cases, as a best practice Nutanix recommends to separate the 10G and 1G interfaces into separate bonds to ensure that CVM and user VM traffic always traverse the fastest possible link. … Read More

In last post of AHV Networking series, we learnt the basics of the various bond modes that are available with OVS in AHV. In this post we will learn how to change the bond mode configuration.

Lets jump into lab and start firing some commands.

1: Verify current bond mode.

SSH to any of the AHV host in cluster and run command: ovs-appctl bond/show

This command shows the current bond mode that is configured and the member interfaces that are present in the bond.

Alternatively you can connect to a CVM and run command: allssh ssh root@192.168.5.1 ovs-vsctl show to fetch more information about a bond. 

2: Change Bond Mode from Active/Backup to Balance-SLB

To change bond from active/backup to balance-slb, we can use the allssh command to update bond configuration on all AHV host (that are part of a cluster) in one shot. Command to do this is : allssh ssh root@192.168.5.1ovs-vsctl set port br0-up bond_mode=balance-slb

3: Verify that bond mode has changed

Command: allssh ssh root@192.168.5.1ovs-vsctl show

4: Change Rebalance Interval

In balance-slb mode, default rebalance interval is 10 secs which is too short.… Read More

In last post of this series we learnt few basics of AHV networking. In this post we will learn about network load balancing in Nutanix.

Nutanix networking is based on OVS and the networks are configured via Prism/ACLI. OVS supports 3 bond modes for network load balancing. 

1: Active/Backup

By default the bond mode is in Active/backup mode when AHV is installed. In this mode VM traffic is sent only over one of the physical uplink and rest all uplinks are in passive mode and they become active only when the active uplinks fails.

With a typical NX node you will see 2×10 GB and 2×1 GB NICs and all of them are aggregated together in a bond called bond0(Older AOS)/br0-up (new AOS).

In this mode the maximum throughput of all VMs running on a Nutanix node is limited to 10 Gbps. Active/backup mode is easiest one to configure and there is no additional configuration needed on the upstream switches.… Read More

AHV Networking Overview

AHV uses Open vSwitch (OVS) to connect the CVM, the hypervisor, and guest VMs to each other and to the physical network on each node. When we install AHV, an instance of OVS is created on that host and all instance of OVS across a cluster combines to form a single logical switch.

What is Open vSwitch (OVS)

OVS is an open source software switch implemented in the Linux kernel and designed to work in a multiserver virtualization environment. OVS is a layer-2 learning switch that maintains a MAC address table.

OVS have virtual ports to which the hypervisor host, CVM’s  and the user VMs connect. To learn more about OVS, please refer this article

Below diagram shows high level overview of OVS architecture in general.

Before moving forward in this article, lets revisit few important terminology related to OVS.

• Bridges: It is a virtual switch which manages traffic between physical and virtual network interfaces.

… Read More