Common configuration parameters and environment variables for installing Oracle in Linux

Fs. aio-max-nr = 1048576

It refers to the number of asynchronous IO requests that can be simultaneously owned. The value appears in the/etc/sysctl. conf file. The recommended value is: 1048576, which is equivalent to 1024*1024, or 1024 K.

Fs. file-max = 6815744

This parameter determines the maximum number of file handles allowed in the system. The file handle setting represents the number of files that can be opened in linux.

Kernel. shmall = 2097152

This parameter controls the total number of pages of shared memory that can be used. The size of the Linux Shared Memory Page is 4 kb, and the size of the shared memory segment is an integer multiple of the size of the shared memory page. The maximum size of a shared memory segment is 16 GB, so the number of pages to be shared is 16 GB/4KB = 16777216KB/4KB = 4194304 (PAGE), that is, 16 GB physical memory in 64 bit system, set kernel. shmall = 4194304 meets the requirements (almost twice the original 2097152 ). In this case, you can adjust the shmmax parameter to 16 GB, and modify SGA_MAX_SIZE and SGA_TARGET to 12 GB (the maximum SGA size you want to set, of course, can also be 2 GB ~ 14 GB, and other memory usage such as PGA parameters and OS must be coordinated. It cannot be set to be too full, such as 16 GB)

Kernel. shmmax = 536870912

It is one of the most important parameters in core parameters and is used to define the maximum value of a single shared memory segment. The setting should be large enough to accommodate the entire SGA under a shared memory segment. setting too low may lead to the creation of multiple shared memory segments, which may lead to a reduction in system performance. The main cause of system degradation is that when the instance is started and the ServerProcess is created, multiple small shared memory segments may cause slight system performance degradation at that time (you need to create multiple virtual address segments at startup, when a process is created, the process must be "identified" for multiple segments, which has some impact), but it will not be affected at other times.

Recommended values:

32-bit linux: the maximum value is 4 GB (4294967296 bytes)-1 byte, that is, 4294967295. The recommended value is half of the memory, so if it is a 32-bit system, the value is generally 4294967295. The 32-bit system has a limit on the size of the SGA, so the SGA can certainly be included in a single shared memory segment.

64-bit linux: The recommended maximum value is physical memory-1 byte. The recommended value is half of physical memory. Generally, the value is greater than SGA_MAX_SIZE, and the physical memory can be-1 byte. For example, for 12 GB physical memory, 12*1024*1024*1024-1 = 12884901887 is recommended, and SGA will certainly be included in a single shared memory segment.

Kernel. shmmni = 4096

This parameter is the maximum number of shared memory segments. The shmmni default value is 4096, which is generally enough.

Kernel. sem = 250 32000 100 128

Take kernel. sem = 250 32000 100 128 as an example:

250 is the value of semmsl, indicating the maximum number of semaphores that can be included in a semaphore set.

32000 is the value of semmns, indicating the maximum number of semaphores allowed in the system.

100 is the value of semopm, indicating the number of operations that a single semopm () call can perform on a semaphore set.

128 is the semmni value, indicating the total number of system semaphores.

Net. ipv4.ip _ local_port_range = 9000 65500

Indicates the range of IPv4 ports that an application can use.

Net. core. rmem_default = 262144

The default value of the buffer size for receiving sockets.

Net. core. rmem_max = 4194304

Indicates the maximum size of the socket receiving buffer.

Net. core. wmem_default = 262144

The default value of the buffer size sent by the socket.

Net. core. wmem_max = 1048586

Indicates the maximum size of the buffer sent by the socket.

 

$ DISPLAY = local_host: 0.0; export DISPLAY

Only when the DISPLAY environment variable is configured can the graphical installation interface of Oracle be displayed and operated on the remote connection terminal session. Local_host can also be written as an IP address.

 

Mkdir/mount_point/tmp

Create a temporary directory tmp, which is located under/mount_point.

 

Chmod a + wr/mount_point/tmp

Modify the tmp directory permission. read and write permissions are added to all users and groups.

Chmod u indicates to modify the permissions of the user

Chmod g indicates to modify the permissions of the Group

Chmod o is used to modify the permissions of other users and groups.

Chmod a indicates to modify the permissions of all users and groups.

$ TMP =/mount_point/tmp

Set the TMP environment variable to "/mount_point/tmp", that is, the temporary directory created earlier.

 

$ TMPDIR =/mount_point/tmp

Set the TMPDIR environment variable to "/mount_point/tmp", that is, the temporary directory created earlier.

 

$ Export TMP TMPDIR

Make the environment variables TMP and TMPDIR take effect for the current session and the user.

 

$ ORACLE_BASE =/u01/app/oracle

Set ORACLE_BASE environment variables. This variable is used to indicate the Home Directory of the ORACLE software installation.

 

$ ORACLE_SID = sales

Set the ORACLE_SID environment variable. This variable is used to indicate the Instance name of the ORACLE database.

 

$ Export ORACLE_BASE ORACLE_SID

Make the environment variables TMP and TMPDIR take effect for the current session and the user.

 

$ Unset ORACLE_HOME

Delete the environment variable ORACLE_HOME

 

$ Unset TNS_ADMIN

Delete the environment variable TNS_ADMIN

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