I’ve spent the past 4 months on a fast paced VDI project built upon Nutanix infrastructure, hence the number of posts on this technology recently. The project is now drawing to a close and moving from ‘Project’ status to ‘BAU’. As this transition takes place, I’m tidying up notes and updating documentation. From this, you may see a few blog posts with some quick tips around Nutanix specifically with VMware vSphere architecture.
As you may or may not know, a Nutanix block ships with up to 4 nodes. The nodes are stand alone it terms of components and share only the dual power supplies in each block. Each node comes with a total of 5 network ports, as shown in the picture below.
The IPMI port is a 10/100 ethernet network port for lights out management.
There are two 2 x 1GigE Ports and 2 x 10GigE ports. Both the 1GigE and 10GigE ports can be added to Virtual Standard Switches or a Virtual Distributed Switches in VMware. From what I have seen people tend to add the 10GigE NICs to a vSwitch (of either flavour) and configure them in an Active/Active fashion with the 2 x 1GigE ports remaining unused.
This seems to be resilient, however I discovered (whilst reading documentation, not through hardware failure) that the 2 x 10GigE ports actually reside on the same physical card, so this could be considered a single point of failure. To work around this single point of failure, I would suggest incorporating the 2 x 1GigE network ports into your vSwitch and leave them in Standby.
With this configuration, if the 10GigE card were to fail, the 1GigE cards would become active and you would not be impacted by VMware HA restarting machines in the on the remaining nodes in the cluster (Admission Control dependant) .
Yes, performance may well be impacted, however I’d strongly suggest alarms and monitoring be configured to scream if this were to happen. I would rather manually place a host into maintenance mode and evict my workloads in a controlled manner rather than have them restarted.