Note: OpenVZ machines cannot change their kernel version, so please disregard this tutorial if you are on OpenVZ.
Check kernel version:
uname -r
Kernel upgrade:
rpm –import https://www.elrepo.org/RPM-GPG-KEY-elrepo.org
rpm -Uvh http://www.elrepo.org/elrepo-release-7.0-2.el7.elrepo.noarch.rpm
yum -y install grub2
yum –enablerepo=elrepo-kernel -y install kernel-ml kernel-ml-devel
awk -F/' '$1=="menuentry " {print i++ " : " $2}' /etc/grub2.cfg #View current system kernels
grub2-set-default 0 #Note: set 0 to the index number of the kernel you want to boot.
reboot #Reboot the system
Enable Google BBR:
echo "net.core.default_qdisc=fq" >> /etc/sysctl.conf
echo "net.ipv4.tcp_congestion_control=bbr" >> /etc/sysctl.conf
Save the configuration file:
sysctl -p
Run the following command to check if it was successful:
sysctl net.ipv4.tcp_available_congestion_control
Returns:
net.ipv4.tcp_available_congestion_control = bbr cubic reno
Enter:
sysctl net.ipv4.tcp_congestion_control
Returns:
net.ipv4.tcp_congestion_control = bbr