4 Replies Latest reply: May 15, 2012 7:24 PM by 896905 RSS

    Memory allocations

    896905
      Hi,

      Anyone know what the sys memory allocations are for?

      S# ldm list-devices -a memory
      MEMORY
      PA SIZE BOUND
      0xa00000 32M sys
      0x2a00000 96M sys
      0x8a00000 374M sys
      0x20000000 2G primary
      0xa0000000 18G ldom1
      0x520000000 18G ldom2
      0x9a0000000 18G ldom3
      0xe20000000 7680M


      I was hoping to create another ldom with 8G of memory but only 7680M can be allocated.

      Thanks,
      Paul.
        • 1. Re: Memory allocations
          Liam Merwick
          Those are memory blocks used internally by the virtualisation software - typically the Hypervisor (and they can't be freed up for use by guest domains)
          • 2. Re: Memory allocations
            896905
            Thanks Liam.

            I've noticed that these sys allocations are consistent for the same hardware.

            eg
            T3-1 it is 502M (I have 6 of these and it is the same on all)
            5220 it is 128M (I have 2 of these and it is the same on all)

            Is this documented somewhere?

            Regards,
            Paul.

            Edited by: 893902 on 10/05/2012 17:50
            • 3. Re: Memory allocations
              Liam Merwick
              The amount of memory used is not documented anywhere as it's an implementation detail and liable to vary. You could possibly assume that the value on a platform is a lower bound but there would be no guarantees that some extra memory would not be allocated, if needed, depending on the config.
              • 4. Re: Memory allocations
                896905
                I have had confirmation from Oracle that any free memory can be allocated to guests.

                Whatever free memory exists can be allocated to guests. I guess that means the hypervisor will not try to claim any additional memory.

                Regards,
                Paul.