Howto configure Esxi (Configure HA and FT in ESXi)

Posted on June 26, 2012



Two ESXi Servers = Esxi1 and Esxi2

version of Esxi Servers = 5.0

Vcenter OS = Windows2008R2(64bit)

SAN = iscsi SAN attached on both Esxi Servers

HA and DRS enabled

( This is a very basic setup. Both ESXi Servers have only one NIC and this is used for ISCSi SAN connectivity and also for other traffic )

Please note , its a very basic and quick way to install and configure your ESXi environment with HA and FT support for your Virtual Machines. There are so many features which also available in the ESXi environment.

Following are the topics covered step by step

  • Vmware HA concepts
  • Install ESXi on two machines.
  • Install Vshpere Client on a Desktop machine.
  • Install Vcenter Software on a Windows 64bit machine.
  • Configure Iscsi SAN on both ESXi Servers
  • Configure and test vmware HA
  • Configure FT or Fault Tolerance
  • Few errors resolution while configuring this setup
  • Clear alert sign after failover

1.) Vmware HA concepts

Let see an example how Vmware HA works. See the below snap and Suppose we have three ESXi Servers and each have 10 Virtual Machines hosted. Every Virtual Machine is getting the hardware resources from its own ESXi Server. If one ESXi Server failed who hosted 10 Virtual Machines, these 10 Virtual Machines will be shifted to other two ESXi Servers. See the next snap for references:

2.) Install Esxi Server on two physical machines. See the below articles for how to install ESXi Server.

3.) Install Vsphere Client on any windows machine. THe Vsphere CLient will be use for the administration of your Virtual Machines. See the below articles for how to install Vsphere Client.

4.) Now you need a Windows Server 64bit OS machine , on which the Vcenter software will be installed. On this software we will connect via Vsphere Client and configure HA or either FT for your Virtual Machines.

Now we assume that we have installed ESXi Server on two physical machines , Vcenter Server software is installed on a Windows 2008R2 (in my case I used Windows Server 2008 R2 OS) , and Vsphere Client on a Windows Desktop machine (In my case I have installed on a Windows XP machine with Service Pack 3).

Now see the below step by step snaps to configure the Cluster of two ESXi servers ( on which will later configure HA for the Virtual machines ) . This activity we perform after connecting Vcenter via Vsphere Client.

Now when we click on the new cluster the following wizard will start:

As you see below the Cluster name “ESXi Cluster” created. Now we will add two ESXi machines in the Cluster. See the below wizard in which we add the ESXi host one by one.

Now see below we provide the username and pasword and ESXi hostname so that the ESXi Server can be add in to the ESXi Cluster.

Now see that both ESXi1 and ESXi2 has been added but show errors and ESXi2 is also not visible. But notice under Task that the Status is not completed 100%. As it will be 100% both nodes will show correctly.

The Task should show as the below snap showing.

5.) Configure Iscsi SAN on both ESXI Servers.

Now we will configure Iscsi SAN on both ESXi Servers so that we can keep the .vmdk files of our Virtual Machine on it(Iscsi SAN). See the below step by step snaps for reference:

Connect to ESXi Server one by one via Vsphere Client and configure/connect ISCSI SAN on both machines. So now first we connect with ESXi1

Select the LUN of Iscsi SAN which you want to connect

Now see that you have SAN connected with your one ESXi Server. I you are not able to see the LUN click on Rescan ALL button. (Do same steps on the second ESXi Server).

6.) Configure and test HA

Now we are going to create HA or High Availability. See the following snap step by step to enable HA in the ESXi Server.

Now verify that under Task see the Status show 100% completed

Finally we have enabled the vmware HA functionality. Now create Virtual Machines and run on a specific ESXi Server and while running the Virtual Machine shutdown the ESXi Server. What happen that the Virtual Machine will start on the second ESXi Server.

7.) Configure FT or Fault Tolerance

VMware FT is a option of VMware which offers non stop availability to you Virtual Machine preventing downtime in case of ESXi Server faults. As far as Vmware HA is concern it works as Active Passive but the FT technology gives you Active/UP Virtual Machine on the different ESXi Server with the completely Sync status

You simply enable the FT at your Virtual Machine by right click on the VM and enable the FT.

There are so many disadvantages of FT, few are ,you cant increase the hardware until you disable the FT technology, There is a limit of ram to a certain extent.

8.) Few errors resolution while configuring this setup.

You may see the below errors when configured/configuring the ESXi environment. See the next below snaps related to resolutions

Error # 1 (The Host Currently Has No Management Network Redundancy )

Resolution # 1

The above resolution is also defined in the below vmware links

Error # 2 (Insufficient Resources To Satisfy Configured Failover Level For VsphereHA)

Resolution # 2

9.) Clear alert sign after failover

You will notice that after failover of your VM you ESXi server(which got failed or faulted) may/will be restored but the error message will not clear, Just select the errors from the Task and right click on the error and click on Clear

I thanks here to vmware who give us the opportunity to do POC/test with the help of available trial version of there product.

Posted in: Virtulization