3 Replies Latest reply: Apr 4, 2012 5:30 PM by Satishbabu Gunukula RSS

    Oracle's recommended Swap Size for Solaris 10 Oracle 11gR2 (11.2.0.2)

    yakub21
      I have a solaris server with 16gb of RAM that will subsequently be zoned into three zones to support three separate database instances, one for each zone. Given that physically there is only 16Gb of ram, It is my understanding and experience that I should have 1.5-2 * 4Gb should be at least 6Gb of SWAP per Local Zone.

      Please advise. Thanks
        • 1. Re: Oracle's recommended Swap Size for Solaris 10 Oracle 11gR2 (11.2.0.2)
          teits
          yakub21 wrote:
          I have a solaris server with 16gb of RAM that will subsequently be zoned into three zones to support three separate database instances, one for each zone. Given that physically there is only 16Gb of ram, It is my understanding and experience that I should have 1.5-2 * 4Gb should be at least 6Gb of SWAP per Local Zone.

          Please advise. Thanks
          This depends also on the type of workload of the databases. For example, if it’s a DSS that contains huge data to be analyze...there should be more RAM available/Swap (e.g for activity like sorting/pga). So your 4gb may not be enough! for that database workload. You can compliment it by giving more space to the SWAP(better increase RAM for performance benefits). I would advise also that your SWAP partition be the most outer part of your disk
          and on different partitions each.


          HTH

          Tobi
          • 2. Re: Oracle's recommended Swap Size for Solaris 10 Oracle 11gR2 (11.2.0.2)
            bigdelboy
            yakub21 wrote:
            I have a solaris server with 16gb of RAM that will subsequently be zoned into three zones to support three separate database instances, one for each zone. Given that physically there is only 16Gb of ram, It is my understanding and experience that I should have 1.5-2 * 4Gb should be at least 6Gb of SWAP per Local Zone.

            Please advise. Thanks
            I'd look at it like this .....

            Your Phyiscal Memory will be used somewhat as follows:-

            - Lets say 1GB for the OS ...
            - 1.5GB for zfs arc cahce if your useing ZFS.
            - The sum of your PGAs and SGA's should fit within the remainder of ram.
            - And your may want a little more to be sure and for other things; monitroting software agents, em etc.

            In order that you can use more virtual memoy than you have physical memory for your will porably want to add a swap file, and for a 16GB machine this would probably be 4 / 8 or perhaps up to 16GB depending if would will occasionally have higher virutal memory demands or if poeple but big files in /tmp. In general swap -s can be used to monitor a shortage, though it can foolled if zfs_arc_cache is not limited.

            ....

            The situation for zones not different unless you are using zone.max-swap and the physical capped memory.

            If you have zone with a physical capped memory of 5GB, and a zone.max-swap of 8GB with is af the zone has a swapfile of 3GB; and you have to make sure:
            - The global zone is able to give that amount of memory to the non-global zone.
            - The global zone can provider the zone.max.swap from its virutal memory.
            - That the sga+pga and /tmp usage and other will fit in zone.max-swap ... use swap -s in the zone to monitor.
            • 3. Re: Oracle's recommended Swap Size for Solaris 10 Oracle 11gR2 (11.2.0.2)
              Satishbabu Gunukula
              You might want to check this

              http://docs.oracle.com/cd/E11882_01/install.112/e24616/presolar.htm#CHDGCIAE

              Hope this helps,

              regards
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