VMware HA % Admission Control Calculator

How to Use the calculator:

Input Fields : Number of ESXi Hosts in Cluster : Min Value : 2 : Max Value : 32
Input Fields :Hosts Failure Cluster Tolerates : Min Value : 1 : Max Value : 31
Output Field : % resources

5 Replies to “VMware HA % Admission Control Calculator”

  1. Samir,
    I am doing an analysis for a client and I am showing they have an unbalanced cluster.
    20 Hosts and all have dissimilar CPU and Memory. How do you calculate something like this for HA? Ive never come across an unbalanced cluster before. What are the impacts? any advice Id appreociatte. Thank You Samir.

    • Extremely sorry for the late response haven’t been blogging due to time constraints.

      In your situation you should look at using the the % resources reserved for the HA failover capacity. You should have a % reservation set greater than or equal to the largest host resources. However in the long run advise the client to maintain homogeneous hardware in the cluster.


  2. Hi Samir,

    Great tool. I plan to use it for my work. Is there an Excel of the same, which is shareable ?

    The idea is to put this as a tab in Excel while I build my overall costing for a given customer proposal.


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