Change the vmnic order on vSphere 6.x

There is always one ESXi host who thinks he’s special and therefore has a different configuration than its siblings. This week it was a brand spanking new UCS blade server that didn’t want to play nice and the result was a different vmnic order.

I’ve done this fix several times before with the older versions (< v5.5) of vSphere but now it was vSphere 6.0 so the KB article 2019871 that describes how to do this up to version 5.1 did not apply any more. But all the way at the bottom there is a link to KB article 2091560 that describe how to do this with vSphere 6.x!

How to change the vmnic order

Log on to your “special” ESXi host with your favorite SSH client.

Run the following command to see the current assignment of aliases to device locations:

The output will look as follows:

Then to reassign an alias run the following command:

For example, if you want to swap vmnic3 and vmnic4 use the following commands:

After you re-assigned the aliases perform a clean reboot of the ESXi host and you’re done!

Optimize ESXi for EMC XtremIO

For a project I’m currently working on, I was asked to document the ESXi hosts recommended / optimal settings required to get the best performance from an EMC XtremIO Storage Array. This was a good opportunity for me to dive a little bit deeper in the configuration, do some performance testing and share the results.

ESXi XtremIO

ESXi XtremIO Host Settings

Set the maximum number of consecutive “sequential” I/Os allowed from one VM before switching to another VM: Read More