How to install updates for Centos.

Open up a terminal application or log in using ssh command. Run the yum command to upgrade all installed packages on CentOS Linux system:

$ sudo yum update

One can only apply security related updates to the server, run:

sudo yum --security update

How to update a single package? Run the following command:

sudo yum update pkg_name
sudo yum update nginx
sudo yum update php
sudo yum update httpd

It is also possible to install all updates except kernel and php packages as follows:

sudo yum -x 'kernel' -x 'php' update

The -x option exclude packages specified given name. See “Force yum update Command To Exclude Certain Packages” for more info.

Reboot the Linux system

sudo reboot

You must reboot system when CentOS Linux kernel gets updated, run:
sudo reboot

Verify Linux kernel version and list updates:

uname -mrs
sudo yum check-update