3 Replies Latest reply: Aug 15, 2012 7:52 AM by 955802 RSS

    Does kernel-uek for i686 support PAE features ?

    955802
      Hello,

      I have a new database server with 128 GB of RAM. On this server I'm obliged to install 11gR2 32 bit, so to receive full support I'm obliged also to install a 32bit OEL.

      If I use the el5 kernel with OEL 5.7 I can see only 64 GB of RAM, but I would like to install UEK . I didn't find any PAE unbreakable kernel, how can I modify UEK to see 64 GB of RAM ?


      Regards .
        • 1. Re: Does kernel-uek for i686 support PAE features ?
          Avi Miller-Oracle
          952799 wrote:
          I have a new database server with 128 GB of RAM. On this server I'm obliged to install 11gR2 32 bit, so to receive full support I'm obliged also to install a 32bit OEL.
          Why are you obliged to run the 32-bit version of 11gR2? You are wasting a lot of that server by installing a 32-bit operating system and a 32-bit database, even with a PAE kernel.
          If I use the el5 kernel with OEL 5.7 I can see only 64 GB of RAM, but I would like to install UEK . I didn't find any PAE unbreakable kernel, how can I modify UEK to see 64 GB of RAM ?
          You can't. You should use 64-bit Oracle Linux with the UEK to see all 128GB of RAM.
          • 2. Re: Does kernel-uek for i686 support PAE features ?
            Catch-22
            Installing Linux x86_64 will probably be your only option if you use RHEL or Oracle Linux 5 or later.

            Under Enterprise Linux 5 there are kernel limitations that allow you to use only up to 16 GB reliably before you can run into lowmem starvation issues. The situation was different with EL3 and 4 and the hugemem kernel, which provided more lowmem space to manage the amount of physical RAM.

            http://docs.oracle.com/cd/E11882_01/server.112/e10839/appi_vlm.htm

            Red Hat Enterprise Linux 5/ Oracle Linux 5 on 32-bit does not have the hugemem kernel. It supports only the 3GB user process/ 1GB kernel split. It has a PAE kernel that supports systems with more than 4GB of RAM and reliably upto 16GB. Since this has a 3GB/1GB kernel split, the system may run out of lowmem if the system's load consumes lots of lowmem. There is no equivalent kernel for hugemem in Enterprise Linux 5 and one is recommended to either use Enterprise Linux 4 with hugemem or go for 64-bit.
            • 3. Re: Does kernel-uek for i686 support PAE features ?
              955802
              Thanks a lot for sharing with me your knowledge.