13 Replies Latest reply: Sep 27, 2012 8:02 AM by Helios-GunesEROL RSS

    Setting Kernel Parameters

      Hi all,

      OS : RHEL 5.7 64 bit
      DB : 64 bit

      I have 32 GB of RAM on production server. My database size is only 12Gb and SGA for db is 4Gb.
      I have read that SHMMAX is nothing but the "maximum bytes in one shared memory segment size". According to this my understanding is that it is nothing but the maximum size of SGA per server. And I have also read that SHMMAX size should not be greater than 4G.

      If im not wrong SHMMAX size must be greater than SGA but in my case SHMMAX size is 512M and my db is running fine.
      Can anyone explain the relation betwwn SGA and SHMMAX?