maybe you want to run your own version of the kernel and you will have to prevent during an automatic update that this kernel will get „replaced“.

same goes with firefox, thunderbird and LibreOffice

yum and apt might not install the latest latest version of those things – and in order to not overwrite your custom/manual installed latest software you will have to:


do not install kernel packages during yum udpate/yum ugprade:

vim /etc/yum.conf
# add this line
exclude=kernel* icedove* thunderbird* firefox*
# now when you run
yum update && yum upgrade
# it should say nothing about „kernel“


To hold a package:

apt-mark hold <package-name>

To unhold a package:

apt-mark unhold <package-name>