VMware Fault Tolerance: what is it and how does it work?

Here you will find out:

what is VMware fault tolerance

how does it work

when DiskInternals can help you

Are you ready? Let's read!

VMware fault tolerance example

What is VMware fault tolerance?

The protected virtual machine immediately switches to the "shadow" copy stored on another ESX server when the host hosting the primary functional copy of the virtual machine dies. This is one of the VMware technologies created to protect virtual machines utilizing continuous availability clusters.

For machines protected with VMware Fault Tolerance, around-the-clock copying of the entire state of memory and processor instructions from the main copy to the shadow copy occurs.

When the main ESX host fails, users should not even notice the process of switching to the second node - there will be no pauses or interruptions with fault tolerance VMware.

What are work principles in vSphere fault tolerance?

If there is an unexpected failure of the host on which the main virtual machine is running, in which case, the additional virtual machine is activated in the same second to replace the main virtual machine.

Fault Tolerance-enabled virtual machines must be in a VMware HA cluster. This ensures that the virtual machine will not experience availability problems in the event of a host failure with the primary VM. The protected and secondary VMs must be located on different ESX hosts. In order to check this condition, the rule works VMware DRS anti-affinity rules by default.

Both machines should have the same family of CPU models, and even better, if they are with the same stepping. FT machines must be located in a shared repository. Supported FC/iSCSI/NFS repositories.

VMware fault tolerance requirements

Any processor that interacts with host machines for fault-tolerant virtual machines must be tested for compatibility with vSphere vMotion. In addition, the preferred hardware environment is MMU (Intel EPT or AMD RVI).

The following processors are supported:

Main processors that can be used in fault tolerance VMware;

AMD Bulldozer and later;

Intel Sandy Bridge and earlier.

And yet, it's better to use 10 Gigabit NICs with Jumbo Frames enabled.

How to recover data from VMware VM

Regardless of what reason you deleted or damaged VMDK files, they can become available again with DiskInternals VMFS Recovery. This application, with professional clarity, restores VMware® data, reads and restores VMDK files, as well as restores VMFS.

DiskInternals VMFS Recovery can also return VMDK files to VMware vSphere or ESX/ESXi servers. Using the wizard when working with the application is also accessible and justified for confidence in the correctness of their actions. All recovered data (folders, files) are exported to local or remote locations.

The following is the flowchart for DiskInternals VMFS Recovery.