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
net.ipv4.ip_forward=0

# 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
Attachments
There are no attachments for this article.
Comments
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
Increase A VMware Disk Size (VMDK) Formatted As Linux LVM without rebooting
Viewed 15427 times since Wed, May 30, 2018
How To Use Systemctl to Manage Systemd Services and Units
Viewed 7506 times since Mon, Dec 7, 2020
Linux - How to get Memory information
Viewed 1939 times since Fri, Jun 8, 2018
How to convert RAW image to VDI and otherwise
Viewed 15026 times since Wed, Oct 3, 2018
Linux - How to monitor CPU usage
Viewed 6472 times since Fri, Jun 8, 2018
Creating SWAP partition using FDISK & FALLOCATE commands
Viewed 3460 times since Thu, Jan 16, 2020
Automatic YUM Updates with Yum-cron
Viewed 10629 times since Fri, Oct 26, 2018
RHEL: Extending a vmdk (Virtual Machine disk)
Viewed 4176 times since Sun, May 27, 2018
What Is /dev/shm And Its Practical Usage
Viewed 8008 times since Tue, Mar 12, 2019
LVM: Extend an existing Logical Volume / Filesystem
Viewed 2488 times since Sat, Jun 2, 2018