linux系统参数修改命令
linux-yvmf:~ # man sysctl 
Reformatting sysctl(8), please wait...
SYSCTL(8)                                                              SYSCTL(8)






NAME
       sysctl - configure kernel parameters at runtime


SYNOPSIS
       sysctl [-n] [-e] variable ...
       sysctl [-n] [-e] [-q] -w variable=value ...
       sysctl [-n] [-e] [-q] -p <filename>
       sysctl [-n] [-e] -a
       sysctl [-n] [-e] -A


DESCRIPTION
       sysctl  is  used  to modify kernel parameters at runtime.  The parameters
       available are those listed under  /proc/sys/.   Procfs  is  required  for
       sysctl(8) support in Linux.  You can use sysctl(8) to both read and write
       sysctl data.


PARAMETERS
       variable
              The name of a key to read from.  An example is kernel.ostype.  The
              '/' separator is also accepted in place of a '.'.


       variable=value
              To  set  a key, use the form variable=value, where variable is the
              key and value is the value to set it to.  If  the  value  contains
              quotes  or  characters which are parsed by the shell, you may need
              to enclose the value in  double  quotes.   This  requires  the  -w
              parameter to use.


       -n     Use  this option to disable printing of the key name when printing
              values.


       -e     Use this option to ignore errors about unknown keys.


       -N     Use this option to only print the names. It  may  be  useful  with
              shells that have programmable completion.


       -q     Use this option to not display the values set to stdout.


       -w     Use this option when you want to change a sysctl setting.


       -p     Load   in   sysctl   settings   from   the   file   specified   or
              /etc/sysctl.conf if none given.


       -a     Display all values currently available.


       -A     Display all values currently available in table form.

EXAMPLES（示例）
       /sbin/sysctl -a


       /sbin/sysctl -n kernel.hostname


       /sbin/sysctl -w kernel.domainname="example.com"


       /sbin/sysctl -p /etc/sysctl.conf



FILES（命令对应的系统参数文件）
       /proc/sys /etc/sysctl.conf


SEE ALSO
       sysctl.conf(5)


    修改完成后