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Considering VSA for ROBO? Please read this!

After fielding a number of questions around this topic recently, its come to my attention that there is a misunderstanding on how to implement the vSphere Storage Appliance (VSA) for certain ROBO solutions. The requirement around the tie-breaker code (VSA Cluster Service) is either misunderstood or misinterpreted when it comes to 2 node VSA deployments at remote office/branch office (ROBO) sites.

Let’s be clear about it now – the VSA needs 3 votes in order to function correctly as a cluster. In a 3 node VSA deployment, this is not an issue since each node gets a vote. In a 2 node VSA deployment, the third vote is handled by the VSA Cluster Service aka the tie-breaker code.

Now, in standard (non ROBO) 2 node VSA deployments where the vCenter is located in the same datacenter as the VSA, the VSA Cluster Service can exist on the vCenter server. During VSA installation, you simply provide the IP address of the vCenter server for the VSA Cluster Service.

However, in ROBO deployments, things are a little different. In these deployments, the vCenter server is typically located at a central office, and the 2 node VSA is deployed at a remote office. The third vote (tie-breaker code) must also be located at the remote office/branch office. To cater for this, we allow the VSA Cluster Service to be decoupled from vCenter and installed in a VM. The VM can be running on a non-VSA ESXi host or Workstation at the branch office. We cannot have it run on the ESXi hosts involved in the VSA cluster because if we lost the host on which the tie-breaker VM was running, we lose 2 votes, and thus the cluster quorum. So it must exist outside of the VSA.

VMware provides VSA Cluster Service installation documentation for the different platforms that we support.  Currently there is Standalone VSA Cluster Service for Linux and a Standalone VSA Cluster Service for Windows. The VSA Cluster Service platform must be on the same subnet as the VSA cluster members.During the install, then installer will ask for details of which host has the tie-breaker code, so the VSA Cluster Service must be installed first. The VSA Installation wizard will then audit this, making sure that it can reach and communicate to the VSA Cluster Service code.

Please make sure you take into account the requirement for the VSA Cluster Service at the remote office/branch office site when designing or achitecting 2 node VSA ROBO solutions.

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Cormac Hogan

About Cormac Hogan

Cormac Hogan is a Senior Staff Engineer in the Office of the CTO in the Storage and Availability Business Unit (SABU) at VMware. He has been with VMware since April 2005 and has previously held roles in VMware’s Technical Marketing and Technical Support organizations. He has written a number of storage related white papers and have given numerous presentations on storage best practices and vSphere storage features. He is also the co-author of the “Essential Virtual SAN” book published by VMware Press.

9 thoughts on “Considering VSA for ROBO? Please read this!

  1. iwan rahabok

    Thanks Cormac for the info. Tricky situation indeed when the 2 boxes are completely isolated and the entire office only has these 2 boxes. Looks like it has to be a “server” (low end tower server machine). In future, can it be a network switch or a cloud service (assuming the machine can connect to internet)? Thanks from Singapore.

  2. aenagy

    Our users would find it very difficult to find the physical space or budget dollars for even a cheap third physical machine. I second the other poster’s comment about being able to use some off-premise solution, either in a corporate data center or third-party.

  3. Martin Michaelis

    Hi cormac,

    since the last entry is from november, i wanted to know if there are any news about the consideration of other options for 2-node ROBO deployments?

  4. Mauro Brunetti

    Hi Cormac !
    Thanks for your information, but i still have a problem.
    When i start the installation from VSA on the remote site, the first part run very good, i have a installed VSA CLuster Service on a local host and pointed to him.
    During the configuration, the install will send OVF file on remote hosts to be configured as VSA cluster ( 2 nodes) but this operation fails after 2 ours … ( 28%)
    I have found that the ovf files is about 1 GB and we have a 2Mbs line, then he take to long… do you have a id how we can have this OVF locally and use it locally, or it is a parameter to have a long windows time for the installation before the time out ?
    Thanks for your answer.

  5. Mike Schreiner

    We have two HP DL360p Gen8 hosts. Each host has 1 quad port nic. Each port is 1 GB.
    Will this work?
    We cannot get this to work to save our lives.
    We have our network configuration exactly as you see on the following blog.
    And we keep getting the following error-
    “ESXi host does not contain multilpe NICs with online ports. NIC redundancy cannot be provided.
    NIC Teaming is not properly setup for port group VSA-Front End. Please refer to VSA online help for more information on network setup for brownfield installations.”


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