Virtualization Team

I have seen tons of articles talking about the differences between VMware ESX & VMware ESXi, but I have not seen many that discuss when to use them. I have noticed that many of my customers get even more confused when reading comparisons between the two, as not all of them have deep understanding of the Virtualization Technology. That means they got to know the differences, but still wondering which one is best fit for their environments. Below is few rules that can put you on the right path.

If you are as paranoid with redundancy as my team & I are, then entering the hostnames & IPs of all the server in a cluster into the VMware host file is a must. As your VMware HA is dependant on your servers being able to resolve the names of itself & other ESX server in the cluster, the DNS get to play a major role in HA. What if DNS fail? As many customers are using Microsoft DNS as their primary means of DNS, there is a chance it will fail a day or another. Would you like a way to ensure that your HA will work even if your DNS fail? then Adding these records to the host files of each of the ESXi server in the cluster will do the trick. What if you did not even have a DNS & still want to implement HA & other feature that depend on name resolution, then again adding the records to the host file is the solution.

Did the title bring your attention? Have you heard that one of the main reasons for VMware ESXi was to get rid of the service console? Are you sure there is no console in VMware ESXi? The true is there is still a very tiny console in VMware ESXi, though it has way smaller foot print than the one found in the ESX version. In addition, the usage of the VMware ESXi Console Access is not supported unless if instructed by VMware to do so. Please use this tip wisely & don’t try to do wild changes using your VMware ESXi console as that is not supported. Yeah, again I would repeat its not supported .

In the past few weeks, I had been hit by many calls of many of my colleagues & customers being hit by the following error when trying to configure VMware ESXi HA:

“cmd addnode failed for secondary node: /opt/vmware/aam/bin/ft_startup failed to complete within three minutes”

After investigating the error for sometime & searching on the internet I found many misleading trial and error solutions for this error around Google results. The resolution which seems to work for everyone of my colleagues & customers is below.

1- Disable HA for the affected cluster

2- Delete the User Worlds Swap file called uwswap from all the nodes in the problematic cluster.

3- Enable HA for the affected cluster again.

A good amount of ESX admins ask on dialy basis how to change the VMware ESX Service Console Vlan using command line. As I decided to save time by writing the steps for these kind of questions to send it to others when asked. I will document these commands in here:

First of all check which vSwitch the Service Console is on (and the name of the Service Console) with esxcfg-vswitch -l (Note: The default service Console switch is vSwitch0 & default name is “Service Console”.)

To set a vlan id on the service console use:

esxcfg-vswitch vSwitch0 -v X -p “Service Console” (Replace X with the desired VLAN number)

I had always been using the VMware ESX version in my implementation. As I noticed that VMware seems to be pushing toward the move to ESXi, I had decided to try the latest version for a full scale installation. Though when I was trying to configure HA for my VMware ESXi Cluster, I had been hit with the below error:

HA agent has an error : Host in HA Cluster must have userworld swap enabled

Luckily the VMware support was quite helpfull as the usual and gave me the simple solution for the problem in less than a minute, I was back up and running with HA configured. So I decided to share the solution with you. Read below the steps for the solution: