My Oracle Support Banner

OS Configuration for large SGA (Doc ID 225220.1)

Last updated on JANUARY 29, 2022

Applies to:

Oracle Cloud Infrastructure - Version N/A and later
Linux OS - Version 2.6 and later
Linux x86
Linux Kernel - Version: 2.6


This document aims to guide Linux system administrators on Red Hat Enterprise Linux 2.1 to configure Very Large Memory and big SGA for Oracle RDBMS with shmfs and bigpages.

For bigpages, see Note:The Bigpages Feature on Linux <>.


To view full details, sign in with your My Oracle Support account.

Don't have a My Oracle Support account? Click to get started!

In this Document
 How to implement the ability of using a big SGA?
 Changes that are to be made at system level
 1.Lowering MAPPED_BASE
 2. Create the shmfs
 3. Enable Big Pages and Add 'bigpages=<size>MB' to the boot loader file.
 4.Modify shmmax
 Changes that are to be made at the Oracle level
 1.Modify the init<sid>.ora
 2.Relocating the SGA:

My Oracle Support provides customers with access to over a million knowledge articles and a vibrant support community of peers and Oracle experts.