Memory Requirements for Oracle 11g

The following are the memory requirements for installing Oracle Database 11g release 2 (11.2):

■ At least 1 GB of RAM

To determine the RAM size, enter the following command:

# grep MemTotal /proc/meminfo

If the size of the RAM is less than the required size, then you must install more memory before continuing.

■ The following table describes the relationship between installed RAM and the configured swap space requirement:

Note: On Linux, the HugePages feature allocates non-swappable memory for large page tables using memory-mapped files. If you enable HugePages, then you should deduct the memory allocated to HugePages from the available RAM before calculating swap space.

Available                                  RAM Swap Space Required

Between 1 GB and 2 GB            1.5 times the size of RAM

Between 2 GB and 16 GB          Equal to the size of RAM 

More than 16 GB                       16 GB

■ To determine whether the system architecture can run the software, enter the following command:

# grep "model name" /proc/cpuinfo

Note: This command displays the processor type. Verify that the processor architecture matches the Oracle software release that you want to install. If you do not see the expected output, then you cannot install the software on this system.

To determine the size of the configured swap space, enter the following command:

# grep SwapTotal /proc/meminfo

If necessary, refer to the operating system documentation for information about how to configure additional swap space.

To determine the available RAM and swap space, enter the following command:

# free

Note: Oracle recommends that you take multiple values for the available RAM and swap space before finalizing a value. This is because the available RAM and swap space keep changing depending on the user interactions with the computer.

Automatic Memory Management

Starting with Oracle Database 11g, the Automatic Memory Management feature requires more shared memory (/dev/shm)and file descriptors. The shared memory should be sized to be at least the greater of MEMORY_MAX_TARGET and MEMORY_TARGET for each Oracle instance on that computer. 

To determine the amount of shared memory available, enter the following command:

# df -k /dev/shm/

Note: MEMORY_MAX_TARGET and MEMORY_TARGET cannot be used when LOCK_SGA is enabled or with HugePages on Linux.