2 Replies Latest reply on Dec 6, 2019 6:33 AM by larstr

    vSAN cluster usable disk space calculation

    esxi1979 Hot Shot

      Hi All

       

      I have 3 servers, each server has 1 ssd & 3 hhd disk 1 TB each. How can i calculate usage size of cluster ? i was told by vmware 80% of (3*3 = 9 ) 9 TB and substract overhead , and overdead size is  difficult to estimate

       

      Any suggestions Please ?

       

      Thanks

        • 1. Re: vSAN cluster usable disk space calculation
          esxi1979 Hot Shot

          i found answer

           

           

           

          Only magnetic disks (HD) will be used for capacity, and that is the total capacity you will have. Depending on the "failures to tolerate" you will select per VM there will be an x number of copies of your data. So if you add the above up you will have the "raw" capacity, depending on the chosen number of copies your net results will vary.

           

          So my calculation will be 

           

          FT=1

           

          9 TB raw

          4.5 TB usable

          80% should be target  usage to avoid data cruching

           

          3.6 TB is the final #

           

          thanks @depping

          • 2. Re: vSAN cluster usable disk space calculation
            larstr Virtuoso
            vExpert

            esxi1979,

            Also note that if you go to Cluster / Monitor / vSan / Capacity you will find a capacity calculator for your environment:

             

            It will make an estimate for you depending on the storage policy you choose.

             

            Lars