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    High availability - host failure number

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    • F Offline
      fred974
      last edited by

      Hi,

      I have enabled HA in my pool of 4x host running xe pool-ha-enable heartbeat-sr-uuids=<UUID>.

      QUESTION: Do I also need to set the maximum host failure number? As I have 4x hosts, am I correct to think that I will need to set it to 3?

      [09:31 uk ~]# xe pool-ha-compute-max-host-failures-to-tolerate
      4
      

      Do I simply leave everything as is or do I manually set the value to 3 with xe pool-param-set ha-host-failures-to-tolerate=**3** uuid=<Pool_UUID>

      Thank you

      henri9813H 1 Reply Last reply Reply Quote 0
      • henri9813H Offline
        henri9813 @fred974
        last edited by

        Hello @fred974

        Did you find your answer ?

        I don't understand clearly how a 4 nodes pool can tolerate 4 nodes dead.

        1 Reply Last reply Reply Quote 0
        • nikadeN Offline
          nikade Top contributor
          last edited by nikade

          Think of it like this:

          If you have 4 hosts, each host maximum usage will be 25% of the total - How much of that % do you want to reserve in case of a failed host?
          Personally, I'd like to have the number set to 1 host (25%) because that means im able to use 3 hosts and the 4th hosts resources would be reserved in case of a failure.

          henri9813H 1 Reply Last reply Reply Quote 0
          • henri9813H Offline
            henri9813 @nikade
            last edited by

            Hello, @nikade

            Yeah i think like this already, but i'm surprised by the result of the calcul.

            I should i have either: 3 nodes which can die, or "1", but i should not have the same number right ?

            in my case, i run the command in a 3 hosts cluster and it return me 3 as value. which disturb me.

            Best regards,

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