4 Replies Latest reply: Sep 13, 2012 2:24 PM by 926398 RSS

    amm vs asmm?

    926398
      I am configuring some systems for huge memory pages on linux and I see in all of the docs that I have read that it says that AMM (automatic memory mgmt) is not compatible with hugepages memory but that ASMM (automatic shared memory mgmt) is compatible with hugepages memory?
      I am confused as to the differences between AMM and ASMM? Can someone enlighten me on this subject?
      Thanks.
        • 1. Re: amm vs asmm?
          JohnWatson
          AMM manages the entire memory of the instance with the parameters memory_max_target and memory_target.
          ASMM manages only the SGA with sga_max_size and sga_target, PGA you have to manage separately with pga_aggregate_target
          • 2. Re: amm vs asmm?
            Veeresh.S
            also AMM is available only from 11g and ASMM was available from 10g.
            • 3. Re: amm vs asmm?
              Aman....
              923395 wrote:
              I am configuring some systems for huge memory pages on linux and I see in all of the docs that I have read that it says that AMM (automatic memory mgmt) is not compatible with hugepages memory but that ASMM (automatic shared memory mgmt) is compatible with hugepages memory?
              I am confused as to the differences between AMM and ASMM? Can someone enlighten me on this subject?
              Thanks.
              Besides the answer of John, have a read of these two posts which explains that why AMM doesn't use Huge Pages.
              http://kevinclosson.wordpress.com/2007/08/23/oracle11g-automatic-memory-management-and-linux-hugepages-support/
              http://blog.tanelpoder.com/2007/08/21/oracle-11g-internals-part-1-automatic-memory-management/

              HTH
              Aman....
              • 4. Re: amm vs asmm?
                926398
                Thanks for the replies, wiish I could give credit to all.