1 Reply Latest reply on Jan 28, 2019 12:20 PM by TheBobkin

    VSAN : disques SSD validés par VMware

    CERKYR Enthusiast


      En vue de l'activation d'un VSAN (witness), il me faut établir un devis pour des disques SSD nécessaires.
      L'objectif est d'en acheter au moins 4 (2 par serveur) (dont 1 en SPARE en ligne par serveur).

      Je rappelle qu'une gros partie des disque SAS de chacun des 2 ESX serviront au VSAN.

      Est-ce que VMware a validé une liste de disque SSD pour DELL R740 ?

      Quelle capacité (Go) faut-il pour ces disques SSD ?

      L'objectif est de pouvoir réaliser un devis.


      J'espère que le VSAN permettra l'exécution d'une VM quelque soit l'endroit où cette VM sera stocké dans le VSAN, surtout en cas de défaillance d'un des 2 ESX, avec redémarrage automatique de la VM avec l'autre ESX, grâce au fonctionnalités HA.



        • 1. Re: VSAN : disques SSD validés par VMware
          TheBobkin Virtuoso
          VMware EmployeesvExpert

          Hello CERKYR,



          Just a reminder that this is an English-speaking Sub-community and thus you will increase the chance you get answers by a) using Google translate or posing questions in English or b) posting on language-specific sub-communities e.g. French


          Via Google-translate:

          In order to activate a VSAN (witness), I need to make a quote for SSDs needed.

          The goal is to buy at least 4 (2 per server) (including 1 in SPARE online per server).

          I remind you that a big part of the SAS disk of each of the 2 ESX will be used for the VSAN.

          Has VMware validated a list of SSDs for DELL R740?

          What capacity (GB) is required for these SSDs?

          The goal is to be able to make an estimate.


          I hope that the VSAN will allow the execution of a VM regardless of where this VM will be stored in the VSAN, especially in case of failure of one of the 2 ESX, with automatic restart of the VM with the other ESX, thanks to the HA features.



          Firstly, just to explain a bit about how vSAN works:

          We use (typically) smaller and faster SSDs for cache-tier and then (typically) larger lower performance SSDs for capacity-tier - note that the cache-tier does not contribute any space to the size of the vsanDatastore only the capacity-tier devices.

          While having hot-spares on hand is always a good idea, providing enough slack-space that everything can be rebuilt can avoid this being necessary and then replace failed devices when/if this occurs.

          Witnesses do not require a physical server to run on and this is a tad wasteful/expensive in my opinion - it sounds like you are planning a 2+1 (DirectConnect) or 1+1+1 (stretched) cluster, if you have some other environment (e.g. ESXi with SAN/NAS) you can run the Witness as a Appliance VM or alternatively host this on the cloud etc.



          "Has VMware validated a list of SSDs for DELL R740?"

          We do not validate/certify devices just for any specific server - any of our certified devices can be used in ESXi-compatible servers, you can check what is certified here:

          (click "Build Your Own based on Certified Components.")


          and here:



          "What capacity (GB) is required for these SSDs?"

          It is unclear from what you said whether you are just looking for sizing devices for a Witness or as cache-tier or capacity-tier as the vSAN storage - please clarify this.


          Default Witness sizings are like so:


          Tiny (10 VMs or fewer)

          2 vCPUs, 8GB vRAM

          8GB ESXi Boot Disk, one 10GB SSD, one 15GB HDD

          Supports a maximum of 750 witness components


          Medium (up to 500 VMs)

          2 vCPUs, 16GB vRAM

          8GB ESXi Boot Disk, one 10GB SSD, one 350GB HDD

          Supports a maximum of 21,000 witness components


          Large (more than 500 VMs)

          2 vCPUs, 32GB vRAM

          8GB ESXi Boot Disk, one 10GB SSD, three 350GB HDDs

          Supports a maximum of 45,000 witness components