Installing the Oracle 11g single-instance database on Oracle Linux 6.5

Oracle Database Preinstallation Task Check hardware requirements

The system must meet the following minimum hardware requirements

Memory requirements

Minimum:1 GB of RAM
Recommended:2 GB of RAM or more

To determine the RAM size, enter the following command:

grep Memtotal/proc/meminfo

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

Note : On Linux, the Hugepages feature allocates non-swappable memory for large page tables using memory-mapped file S. If you enable hugepages and then should deduct the memory allocated to Hugepages from the available RAM before Calcula Ting swap space.
Simple Note : If you use the Hugepages function, the memory allocated to Hugepages is subtracted from memory when the swap space is computed.

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

grep Swaptotal/proc/meminfo

Note : If necessary, see the operating system documentation for information what to configure additional swap Spa Ce.

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

Free

Automatic Memory Management

Starting with Oracle Database 11g, the Automatic memory Management feature requires more shared Memory (/DEV/SHM) A nd file descriptors. The size of the shared memory must is at least the greater of the Memory_max_target and Memory_target parameters For each Oracle instance on the computer. If the Memory_max_target parameter or the Memory_target parameter is set to a nonzero value, and an Incorrect si Ze is assigned to the shared memory, it results in a ORA-00845 error at startup. On linux Systems, if the operating SYSTEM/DEV/SHM mount size is too small for the Oracle system global area (SG A) and program Global Area (PGA), it results in an ora-00845 error.

Simple note : In the case of using AMM, the shared memory/DEV/SHM size must be greater than the size of the Memory_max_target parameter setting.

The number of the file descriptors for each Oracle instance must is at least 512*processes. The limit of descriptors for each process must is at least 512. If file descriptors is not sized correctly, you see a ORA-27123 error from various Oracle processes and potentially Linu X Error emfile (Too many open files) in non-oracle processes.
Simple Description : The number of file descriptors per Oracle process must be at least 512.

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

DF -h/dev/shm/

Note : The Memory_max_target and Memory_target parameters cannot be used while the LOCK_SGA parameter is enabled, or With Hugepages on Linux.

The workaround, if you encounter the ORA-00845 error, are to increase the/dev/shm mountpoint size.
For example:

Mount -t Tmpfs shmfs-o SIZE=7G/DEV/SHM

Persistent across system restarts, add an entry in/etc/fstab similar to the following:

0

Other Notes :

1. On the initialization Parameters page, note the Memory Size (SGA and PGA), which sets the initialization parameter MEMO Ry_target or Memory_max_target. The initialization parameters cannot is greater than the shared memory file system on the operating system. For example, if the shared memory file system allocation on your system was 1 GB, but you set memory Size (memory_target) t o 2 GB, then the following error messages is displayed during database startup:

ORA-00845 not on this systemora-01078 in Processing System Parameters

2. In addition, if you click All initialization Parameters and the global database name is longer than eight characters, T Hen the database name value (in the db_name parameter) was truncated to the first eight characters, and the Db_unique_name Parameter value is set to the global name.

Installing the Oracle 11g single-instance database on Oracle Linux 6.5