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    Any way to know what features will be CPU masked before adding a host to a pool?

    Scheduled Pinned Locked Moved Compute
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    • C Offline
      CodeMercenary
      last edited by CodeMercenary

      I'm interested in more general advice, so this isn't only useful in my specific scenario.

      I'm specifically thinking of adding a host with Intel Xeon E5-2683 v4 CPUs to a pool with hosts that have E5-2697 v4 CPUs. I've done some searching for comparisons between the two CPUs but I'm far from an expert in CPU technology. They are both Broadwell based, seem to have identical features, and were released around the same time. I'm guessing they are just a lower and higher end version of the same processor so there would be no CPU masking if I put them in the same pool.

      Note, the 2683s are in a host that it's highly unlikely I'd want to live migrate anything to, however, dealing with only one pool reduces complexity just a little bit and the hosts are otherwise configured and cabled in a way that being in the same pool would work.

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      • A Online
        Andrew Top contributor @CodeMercenary
        last edited by

        @CodeMercenary They are basically the same CPU. They should have exactly the same features except performance. So it should not be a problem to have them in the same pool. One CPU will just be faster than the other CPU.

        You can look at /proc/cpuinfo in Dom0 or when running the installer to check the CPU features. The flags should be the same.

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        • olivierlambertO Offline
          olivierlambert Vates 🪐 Co-Founder CEO
          last edited by

          xen-cpuid will be the real source of truth. Do it on both machine, and diff it to see if there's any diff (you shouldn't find in your case)

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          • C Offline
            CodeMercenary @olivierlambert
            last edited by

            @olivierlambert Excellent thank you.

            @Andrew In my case, I'd have to check in dom0 since I already had xcp-ng installed on that host, I upgraded and added a second CPU after it was in service. Thank you for confirming what I suspected and for guidance for others trying to answer the same question.

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            • A Offline
              andyhhp Xen Guru @CodeMercenary
              last edited by

              Intel Xeon E5-2683 v4 CPUs vs E5-2697 v4 CPUs

              You are correct. These are adjacent rows in the SKU table; they've got the same core count, and only differ by 500MHz frequency. They're basically identical as far as software is concerned.

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              • C Offline
                CodeMercenary @andyhhp
                last edited by

                @andyhhp Well, then I'm glad I spent $35 each on the 2683s while the company spent $125 each on the 2697s. Saved me $180 and it has all the same functionality but just a bit less speed.

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