Updates can be downloaded using yum downloadonly plugin without actually installing them to the system. Below steps can be followed for that.
Install yum-downloadonly package-name.
# yum install yum-downloadonly
Create a directory to download packages to.
# mkdir /tmp/download
Run yum in the downloadonly mode.
# yum –downloadonly –downloaddir=/tmp/download update
The above command wouldn’t update the system, but would just download the updates to /tmp/download directory. This is the best method to download packages using yum. Command “yumdownloader” provided through “yum-utils” can also be used to download specific single packages.