Linux Kernel Parameter information (related to Oracle)

Command Line: vim/etc/sysctl. conf

Check the setting values of the following two rows:

Kernel. shmall = 2097152

Kernel. shmmax = 4294967295

If the default configuration is greater than the value given here, do not modify the original configuration.

Add the following content at the end of the/etc/sysctl. conf file:

Fs. file-max = 6553600

Kernel. shmmni = 4096

Kernel. sem = 250 32000 100 128

Net. ipv4.ip _ local_port_range = 1024 65000

Net. core. rmem_default = 4194304

Net. core. rmem_max = 4194304

Net. core. wmem_default = 262144

Net. core. wmem_max = 262144

Here, "fs. file-max = 6553600" is actually obtained by "fs. file-max = 512 * PROCESSES,

The value of PROCESSES is 12800, that is, "fs. file-max = 512*12800 ".

After the sysctl. conf file is modified, Run "sysctl-p" to make the settings take effect.

[Root @ localhost ~] # The meanings of common sysctl-p kernel parameters are as follows.

Kernel. shmmax: indicates the maximum value of a single shared memory segment, in bytes. This value is generally half of the physical memory, but it does not matter if it is larger. Here it is set to 4 GB, that is, "4294967295/1024/1024/1024 = 4G ".

Kernel. shmmni: Minimum value of a single shared memory segment, which is generally 4 kb, that is, 4096bit.

Kernel. shmall: indicates the total amount of available shared memory. The unit is page. On the 32-bit system, the previous page equals 4 kb, that is, 4096 bytes.

Fs. file-max: Maximum number of file handles. File handle indicates the number of files that can be opened in Linux.

Ip_local_port_range: indicates the port range, which is the specified content.

Kernel. sem: indicates the set semaphore. The content of these four parameters is fixed.

Net. core. rmem_default: the default value of the buffer size of the received socket (in bytes ).

Net. core. rmem_max: Maximum buffer size of the received socket (in bytes)

Net. core. wmem_default: the default value of the buffer size of the sending socket (in bytes ).

Net. core. wmem_max: maximum size of the buffer for sending Sockets (in bytes ).

Recommended reading:

Linux Kernel Parameter Optimization (for Oracle)

Oracle Linux Kernel Parameter Modification

Setting Kernel Parameters in Linux during Oracle Installation