An often-overlooked configuration feature, that I have seen with VMware clusters, is the configuration of vMotion. You should have at least one physical network adapter dedicated to vMotion traffic. Will one adapter that is dedicated to vMotion work? Of course, it will function just fine. But if your vMotion is configured with a single 1 GbE adapter, it may take a considerable amount of time to complete vMotion operations. Hosts that have many running VMs, and especially those with higher guest memory allocations, will take longer to place a host into maintenance mode as guests are migrated to other hosts. Reducing the time to enter maintenance mode can be an important factor to consider when you are applying ESXi patches, updating the physical host firmware, hardware or software upgrades, etc. If you have the appropriate hardware, using 10 GbE will be much faster compared to 1 GbE. With either type, you can use two, or even more, adapters to improve the guest migration performance.
Improving your vMotion performance
Dedicate more physical adapters to vMotion and then create additional VMkernel interfaces for vMotion. Below is an example of creating a vSwitch for vMotion that uses two adapters. It is a requirement for your VMkernel ports that are used for vMotion to be in the same IP subnet.
- First, create a vSwitch and assign two physical adapters that will be used for vMotion.
- Next, create and configure your first VMkernel port group for vMotion.
- Then on the properties of the port group’s NIC teaming, override the switch failover order. Here you mark the first physical adapter as Active. The second adapter should be marked as Standby.
- Now you create the second VMkernel port group for vMotion.
- On the second port group’s NIC teaming override, the switch failover order should have the second physical adapter marked as Active. The first physical adapter should be then be marked as standby on this port group.
For a detailed configuration, VMware has published the following article; https://kb.vmware.com/s/article/2007467
Adding multiple NICs to your vMotion will improve the performance of migrating guests between hosts, and hopefully help reduce the “wait time” during your maintenance windows. Need more information on server or storage virtualization? Email email@example.com. We are happy to help!