Stability problem
Stock CentOS 7 has an old kernel 3.10.x which is causing major stability issues with AMD Ryzen 7 and the B350 series of motherboards.
Solution
Switch to the newer 4.1x kernel as follows;
Install latest 4.1x kernel from ElRepo
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 --enablerepo=elrepo-kernel install -y kernel-ml
Reboot and select the 4.1x option in Grub boot options screen
Regenerate Grub2 config files
grub2-mkconfig -o /boot/grub2/grub.cfg
Change Grub settings
Edit /etc/default/grub Change GRUB_DEFAULT = saved to 0
Or
List Grub boot options
grep "^menuentry" /boot/grub2/grub.cfg | cut -d "'" -f2
Set default Kernel
grub2-set-default 0 grub2-editenv list
Reboot. Default boot will load the 4.1x kernel.
Verify
uname -r
Disable Kernel Updates
Update: yum installs or updates will revert back to the base kernel version 3.10.x, to stop kernel updates edit /etc/yum.conf and under the [main] section add line
exclude=kernel*
or remember to add the exclude option during yum
yum -x 'kernel*' update