Linux Command sysctl use

Previously did not pay attention to this command, until one time in the unit installed Greenplum, in the absence of configuration system parameters, there is insufficient equipment space error message.

Of course, the installation is not my native, but the public server, editing and modifying system parameters, still error, the modified system parameters did not play an effect, the Internet a check, need reboot.

This server a lot of people are in use, can not reboot, how to do.

To check the system parameters related to the command, there is a sysctl, this is the dynamic modification of the system parameters.

The following is the specific use of this command:

Sysctl command

The SYSCTL command is used to dynamically modify the kernel's operating parameters while the kernel is running, and the available kernel parameters are in directory/proc/sys.

It contains some advanced options for the TCP/IP stack and the virtual memory system. This allows experienced administrators to improve compelling system performance. More than 500 system variables can be read with Sysctl.

Grammar:

Sysctl (option) (parameter)

Options:

- n: No keywords are printed when printing values;

- e: Ignore unknown keyword error;

- n: print name only;

- W: This is used when changing the SYSCTL setting;

- P: Load kernel parameter settings from config file "/etc/sysctl.conf";

-A: Prints all currently available kernel parameter variables and values;

-A: Prints all the currently available kernel parameter variables and values in tabular format.

Parameters:

Variable = value: Sets the value of the variable corresponding to the kernel parameter.

Instance:

To view all the readable variables:

SYSCTL-A read a specified variable,

For example Kern.maxproc:

Sysctl Kern.maxproc kern.maxproc:1044 To set a specified variable,

Directly with variable=value such syntax:

5000 sysctl kern.maxfiles=5000 kern.maxfiles:2088

Linux Command sysctl use