cuda installation error

Hello, I am new to cuda and trying to install it on my server (CentOS). But found this error.
I have followed these steps:-

1.Download base installer (rpm network) 6.2 kb from this site-- https://developer.nvidia.com/cuda-downloads.
2. Followed the instructions as mentioned there.
(A) sudo rpm -i cuda-repo-rhel7-8.0.61-1.x86_64.rpm(B)sudo yum clean all
© `sudo yum install cuda

  1. Following the step mentioned in this guide —http://developer2.download.nvidia.com/compute/cuda/8.0/secure/Prod2/docs/sidebar/CUDA_Installation_Guide_Linux.pdf?bq9BgwglF4TlCtrRQLu2a2dgrkfBbc9eTMsP5eFzy74DktppJJ1i7PmnnMS8wVobkOv1rXI34EzWCWMEI7IvNyGrJUW15wGx4rzNyOR7nU69-mJdULWNTIgtl3JLKIpH7HltMSar8abiCD_-YzsyTdcgBIKDca7qdwkhrFb8kZ3P2tg1f7n35dIMTg.

Then got this error. How could I resolve this error?

Error: Package: 1:nvidia-kmod-384.66-2.el7.x86_64 (cuda)
Requires: dkms
You could try using --skip-broken to work around the problem
** Found 3 pre-existing rpmdb problem(s), ‘yum check’ output follows:
ipa-client-4.4.0-14.el7.centos.7.x86_64 has installed conflicts freeipa-client: ipa-client-4.4.0-14.el7.centos.7.x86_64
ipa-client-common-4.4.0-14.el7.centos.7.noarch has installed conflicts freeipa-client-common: ipa-client-common-4.4.0-14.el7.centos.7.noarch
ipa-common-4.4.0-14.el7.centos.7.noarch has installed conflicts freeipa-common: ipa-common-4.4.0-14.el7.centos.7.noarch

Please HELP!!!

so install dkms

If you google how to install dkms on your distro, you will find instructions

Yeah finally installed. Thanks a lot

As mentioned above, I have installed cuda 8.0 successfully but when i reboot the machine after installation, it directly open terminal. what would I do?

Try startx, or possibly sudo service start, and replace with what ever display manager you use. Some examples are sddm for kde plasma (maybe), xdm, lightdm, gdm… It depends on the display manager you have chosen to use in your os.

I made a lot of assumptions about the setup of your linux system when giving you that advice. I have never personally used a redhat os before, but startx is how you do it if you have xorg installed and configure correctly, or if you have some init.d based scripting thing then the service command should work, maybe for systemd too.