VMware ESX 4.0 FT – Fault Tolerant – Sneak Peek

VMware innovations in operation continuity will be glowing in VMware ESX 4.0.In addition to the current high availability of VMware ESX Server, the software will inherit a function of fault tolerance.Today, VMware High Availability (HA) provides rapid restart of virtual machines in their last known state on a different ESX server, in case the physical server hosting them face a failure.

With VMware FT (Fault Tolerance), the system provides synchronous replication of protected VMs on two different servers.The application continues to function without interruption on the secondary server if the primary server comes to fail.For additional security measure, this cloned VM is automatically replicated to a third server, as the first server is not repaired, to maintain the availability of the VM if the second server also came to the same problem.

Meanwhile, the launch of VMware FT, the only real solution for fault tolerance available in virtualized environment remains hidden and not announced. Thought it was of a great deal that I thought I will share it with everyone, even before it hit the market. To get you more exited about VMware FT check out the below VMware FT Video:

To find out more about the other features of the upcoming VMware ESX release 4.0 check out John article:

VMware News: Features of the new VMware ESX 4.0


  1. VMware ESX 3 supports Fault Tolerance today!

    Since January, VMware ESX 3 has offered full fault tolerance by running on fault tolerant servers from Stratus and NEC. This provides current VMware users with immediate solutions for their most demanding applications – no waiting until ESX 4 arrives some time next year.

    ESX on a true FT platform allows users to run their most demanding applications without the limitation that will come with VMware FT…

    * Not limited to single core VM
    * No performance overhead of Record/Replay
    * No latency issues
    * Elimination, not propagation of transient errors
    * Can run on a single server for edge/SMB environments

    When VMware FT does reach the market, it will be a nice way to increase availability of numerous less demanding applications that today can not be clustered. This will allow data centers to have a complete range of availability from base VMware, through VMware FT, and up to ESX on an ftServer.

    The best of all worlds.

  2. A new project for xen has been released a few days ago which does exactly what vmware FT does…for free. It’s still in the beta stages, however; there is a proof of concept video and the source is avaiable if you dare to try it.

  3. Virtual User says

    I’m confused. At minute 7:29 he reboots the primary ESX server which causes the primary VM to become “unresponsive”. At this time the SSH window is on the VM dekstop in both VMs.

    He then moves at 7:59 to the secondary VM and shows things still moving. He closes the SSH window on the secondary. Moments later the video expands again to show the primary VM again, strangely the SSH window is now closed there as well. But wait, inst that VM down?? How coould the console window replfect the changes of the secondary in lockstep if the primary VM is down?

    It couldn’t have come back up as moments later he shows in the Virtual Center console that the server is still down (not to mention a sserver and it’s VMs cant restart in 30 seconds). Are we being duped here in this video??

  4. Hi Virtual User,

    I believe you are missing one thing about FT. As soon you start FT It will create an exact running replica of the original VM. If the primary VM go down the secondary VM instantaneously take over without any downtime, though right after the failover happen if there is an extra VMware ESX server in there VMware will create a new replica from the old secondary. So the old secondary become to be the new primary for a new VMware FT replica set. So when he show you the primary back after the fail over that was actually the old secondary, and when he show you the secondary at the end of the video that is the new secondary. FT will try to always ensure that you have an extra active replica of your FT protected VM as long you have more than one ESX server & enough resource to do so.

    I hope this help.

  5. Phil Maynard says

    For those of you that would like to extend the capabilities of VMware HA/FT, to detect and automatically repair system and application failures, you might want to check out vAppHA: –


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