RHEL: Displaying/setting kernel parameters - ’sysctl’

RHEL: Displaying/setting kernel parameters - 'sysctl'

# Tested on RHEL 6 & 7

# Setting kernel parameters is a fairly straightforward task. If we check the file
# /etc/sysctl.conf, we will see several attributes with their appropriate values, these are
# the values applied at startup. This file can be edited directly with a text editor, then
# the values reloaded by executing 'sysctl -p'.
# On RHEL 7, default settings are in /usr/lib/sysctl.d/00-system.conf. These default
# settings may be overridden by entering new settings in /etc/sysctl.conf or in an
# /etc/sysctl.d/<name>.conf file.

# These values can also be changed at runtime by modifying the values under /proc/sys.
# For instance, attribute named net.ipv4.ip_forward can be viewed or modified as
# /proc/sys/net/ipv4/ip_forward.

# To view the running value, run:

cat /proc/sys/net/ipv4/ip_forward

# To change the running value, run:

echo 1 > /proc/sys/net/ipv4/ip_forward

# The kernel attributes and values available to change can be found by either browsing the
# /proc/sys folders, or by running 'sysctl -a':

/sbin/sysctl -a | grep net.ipv4.ip_forward

# Lastly, values can be hot modified by running 'sysctl -w' command:

/sbin/sysctl -w

# To fix this change, insert a new line with the parameter in file /etc/sysctl.conf.

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

/sbin/sysctl -p [/etc/sysctl.conf]
0 (0)
Article Rating (No Votes)
Rate this article
There are no attachments for this article.
There are no comments for this article. Be the first to post a comment.
Full Name
Email Address
Security Code Security Code
Related Articles RSS Feed
LVM: Reduce an existing Logical Volume / Filesystem
Viewed 1737 times since Sat, Jun 2, 2018
LVM: Extend SWAP size by adding a new Logical Volume
Viewed 1282 times since Sat, Jun 2, 2018
RHCS6: Mirror/unmirror a GFS2 volume
Viewed 4302 times since Sun, Jun 3, 2018
RHEL: Change system’s hostname
Viewed 2351 times since Sun, May 27, 2018
Top 25 Best Linux Performance Monitoring and Debugging Tools
Viewed 4834 times since Sun, Sep 30, 2018
Linux Find Large Files
Viewed 2045 times since Mon, Oct 29, 2018
How to find the largest files and directories in Linux?
Viewed 2441 times since Sun, May 20, 2018
Easily Find Bugs In Shell Scripts With ShellCheck
Viewed 1964 times since Thu, Apr 18, 2019
Open SSL HowTo: Decode SSL Certificate
Viewed 5152 times since Mon, Feb 18, 2019
How to run command or code in parallel in bash shell under Linux or Unix
Viewed 2014 times since Tue, Aug 6, 2019