Skip to content

Posts tagged ‘ESXi’


Allow Virtual machines with duplicate MAC address on vSphere 5.5

In a migration project to VMware vSphere 5.5 I bumped into duplicate MAC address issue (I found out after some investigation).

Some info on the setup.

There are ESXi hosts that we are migrating from 5.0 to 5.5. Some VM’s where 2 VM’s (VM1 and VM2) share the same MAC address (production and test machine).

On ESXi 5.0 these 2 VM’s can run together on the same ESXi host.

I want to move the VM’s to an already upgraded ESXi 5.5 host, the first VM (VM1 moves without any problems. ) For the second VM (VM2) I get following error during vMotion. Same error happens when I cold migrate the VM2 to the same host (ESXi 5.5) as VM1 and try to power VM2 on.











After some Google research I came across following blog

And adding the advanced setting to VM2 fixed the problem.


Where to find VMware version information

Here some links to find version information about VMware vSphere products

and about VMware Tools versions


How long can an ESXi host run?

Before starting an upgrade at a customer site I was surprised how long an ESXi host can run. Here the proof.



Upgrade ESXi 5.0 to 5.1 via VMware Update Manager : incompatible

Today I am at customer site to upgrade en vSphere environment to the latest and greatest version of VMware vSphere 5.1.

We started the migration process by importing the VMware ESXi image we downloaded from the VMware download website.

In Update Manager we checked the server and saw that the server was not compliant with the new ESXi version so we could start the remediation.

After the remediation started we got the following message in Update Manager stating that the server was incompatible for this upgrade.

After some research on the internet I found following VMware KB 2034945 article.

As pointed out in this article the upgrade worked after a reboot of the ESX host.


Unable to expand VMFS partition

Today I was asked to expand a local datastore of a ESXi 4.1. Expanding a disk is normally no problem when you are able to increate the size of the disk. After increasing the disk size you should be able to increate the partition size.

The ESXi was managed by a vCenter 5.0.  On the storage adapter I did a RESCAN data stores after the disk size was increased.  Then I went into the DATASTORE properties and I saw following













This above view was via a vCenter connection.  Then I found following VMware KB which told me to make a direct connection to the ESXi host.  After going to into the datastore properties I found out that I could increase.











When I selected this local datastore and finished the expansion I saw following result in the vSphere Client direct to the ESXi and via vCenter.











Lucky for the customer this expansion went OK.

Hopefully if you have this problem this KB article fixes also your problem.



Gert Van Gorp