CentOS 7 with Gnome Desktop - As A Physical Machine

1. Download software for CentOS 7

http://isoredirect.centos.org/centos/7/isos/x86_64/

2. Making Installation USB Media
A. USB prepare on Windows you may use either

Fedora LiveUsb-Creator
https://fedorahosted.org/releases/l/i/liveusb-creator/liveusb-creator-3.12.0-setup.exe

or
unetbootin
http://unetbootin.sourceforge.net/unetbootin-windows-latest.exe

B. USB preparing on Linux

su -sudo findmnt /dev/sdb

sudo dd if=/dev/zero of=/dev/sdb bs=512k count=10 # Clean usb flash master boot from any files  

sudo umount /run/media/user/mydisc
sudo fdisk /dev/sdb >> d (delete all partitions from disk) >> w (write changes and quit)
sudo dd if=CentOS-7-x86_64-DVD-1503.iso of=/dev/sdb bs=512k

Using yum with a Proxy Server

sudo vim /etc/yum.conf
# The proxy server - proxy server:port 
numberproxy=http://mycache.mydomain.com:3128
proxy_username=yum-user
proxy_password=yum-user-password

or if proxy is protected by username / password run instead:

export username='yum-user'
export password='qwerty'
export http_proxy="http://$username:$password@your-proxy-server:8080" 

Repo Install

sudo rpm -Uvh http://dl.fedoraproject.org/pub/epel/epel-release-latest-7.noarch.rpm http://li.nux.ro/download/nux/dextop/el7/x86_64/nux-dextop-release-0-5.el7.nux.noarch.rpm http://www.elrepo.org/elrepo-release-7.0-2.el7.elrepo.noarch.rpm http://linuxdownload.adobe.com/adobe-release/adobe-release-x86_64-1.0-1.noarch.rpm

 Software install

sudo yum clean all && sudo yum makecache && sudo yum update && sudo yum upgrade 

sudo yum install -y dkms binutils gcc make patch kernel kernel-firmware kernel-headers kernel-devel glibc glibc-common compat-glibc glibc-devel glibc-headers 

sudo yum install -y ntfs-3g ntfsprogs unrar p7zip p7zip-plugins unetbootin java icedtea-web transmission brasero rhythmbox totem gthumb thunderbird x264* mediainfo mediainfo* ffmpeg libquicktime* gstreamer{,1}-plugins-ugly gstreamer-plugins-bad-nonfree gstreamer1-plugins-bad-freeworld gstreamer1-libav gstreamer-plugin-crystalhd gstreamer1-plugins-bad-free gstreamer1-vaapi flash-plugin smplayer vlc gtk-recordmydesktop skype cinnamon
wget https://dl.google.com/linux/direct/google-chrome-stable_current_x86_64.rpm https://dl.google.com/linux/direct/google-talkplugin_current_x86_64.rpm 
sudo yum install -y ./google-*
# setsebool -P unconfined_chrome_sandbox_transition 0
sudo yum install -y http://dl.fedoraproject.org/pub/fedora/linux/updates/20/x86_64/uget-1.10.4-1.fc20.x86_64.rpm

sudo yum --enablerepo=elrepo install -y kmod-nvidia nvidia-detect nvidia-x11-drv
sudo mv -v /usr/bin/totem-video-thumbnailer /usr/bin/totem-video-thumbnailer.old #bug 

- Cinnamon desktop working fine alternately with Gnome

sudo yum install -y cinnamon

- Google chrome Remote Desktop install

- Install chrome remote desktop extension from this link

https://chrome.google.com/webstore/detail/chrome-remote-desktop/gbchcmhmhahfdphkhkmpfmihenigjmpp

- Convert chrome remote desktop .deb package to .rpm

 wget https://dl.google.com/linux/direct/chrome-remote-desktop_current_amd64.deb
sudo yum install -y alien rpmrebuild
sudo alien -r --scripts chrome-remote-desktop_current_amd64.deb
sudo rpmrebuild -pe chrome-remote-desktop_current_amd64.rpm 
- (using vim editor remove known directories like /opt /etc/ ..etc then save :wq)
vim chrome-remote-desktop_current_amd64.rpm 

- install chrome remote desktop plugin package .rpm you created from .deb
sudo yum localinstall -y chrome-remote-desktop_current_amd64.rpm

- Stop Chrome Remote Desktop:

 sudo /opt/google/chrome-remote-desktop/chrome-remote-desktop --stop

- Backup the original configuration:

sudo cp /opt/google/chrome-remote-desktop/chrome-remote-desktop /opt/google/chrome-remote-desktop/chrome-remote-desktop.bk

- Edit the config file (sudo vim, gksudo gedit, etc):

 gksudo gedit /opt/google/chrome-remote-desktop/chrome-remote-desktop

- Find DEFAULT_SIZES and amend to the remote desktop resolution. E.g.:

  DEFAULT_SIZES = "1920x1080"

- Set the X display number to console (0):

  FIRST_X_DISPLAY_NUMBER = 0

- Comment out sections that look for additional displays:

 # while os.path.exists(X_LOCK_FILE_TEMPLATE % display):
 # display += 1

and

 #logging.info("Starting %s on display :%d" % (xvfb, display))
 #screen_option = "%dx%dx24" % (max_width, max_height)
 #self.x_proc = subprocess.Popen(
 #    [xvfb, ":%d" % display,
 #     "-auth", x_auth_file,
 #     "-nolisten", "tcp",
 #     "-noreset",
 #     "-screen", "0", screen_option
 #    ] + extra_x_args)
 #if not self.x_proc.pid:
 #  raise Exception("Could not start Xvfb.")

- Save and exit the editor. Start Chrome Remote Desktop and reboot you computer:

 touch ~/.chrome-remote-desktop-session
 sudo /etc/init.d/chrome-remote-desktop start
 sudo reboot

IPTables on CentOS 7

sudo yum install iptables-*
sudo systemctl disable firewalld.service
sudo systemctl stop firewalld.service
sudo systemctl enable iptables.service
sudo systemctl enable ip6tables.service
sudo systemctl start iptables.service
sudo systemctl start ip6tables.service

Gnome Extensions (Install Extensions using Firefox)

sudo yum install -y gnome-shell-browser-plugin
https://extensions.gnome.org/extension/6/applications-menu/
https://extensions.gnome.org/extension/442/drop-down-terminal/
https://extensions.gnome.org/extension/721/gnome-shell-open-terminal/
https://extensions.gnome.org/extension/610/minimized-windows-list/
https://extensions.gnome.org/extension/8/places-status-indicator/
https://extensions.gnome.org/extension/156/quit-button/
https://extensions.gnome.org/extension/7/removable-drive-menu/
https://extensions.gnome.org/extension/593/text-translator/
https://extensions.gnome.org/extension/307/dash-to-dock/
https://extensions.gnome.org/extension/495/topicons/
https://extensions.gnome.org/extension/690/easyscreencast/ 

Gnome Shell disable visual effects

gsettings set org.gnome.desktop.interface enable-animations false
gsettings set org.gnome.GWeather temperature-unit "'centigrade'" 
poweroff > gnome-session-quit --power-off --force > alt + ctrl + delete

VirtualBox install

cd /etc/yum.repos.d/
sudo wget http://download.virtualbox.org/virtualbox/rpm/rhel/virtualbox.repo
sudo groupadd vboxusers
sudo usermod -a -G vboxusers oracle
sudo yum update -y
sudo rpm -Uvh http://dl.fedoraproject.org/pub/epel/epel-release-latest-7.noarch.rpm
sudo yum install -y binutils gcc make patch libgomp glibc-headers glibc-devel kernel-headers kernel-devel dkms
sudo yum install -y VirtualBox-4.3
sudo /etc/init.d/vboxdrv setup

KVM Install

lsmod | grep kvm - To check kvm Modules
sudo yum groupinstall -y Virtualization*
sudo chkconfig libvirtd on
sudo /etc/init.d/libvirtd start
mkdir /data/kvm
sudo semanage fcontext -a -s system_u -t virt_image_t "/data/kvm(/.*)?"
sudo restorecon -R -F -v /data/kvm
sudo chcon -R --reference /var/lib/libvirt/images /data/kvm
sudo rm -rf /var/lib/libvirt/images
sudo ln -s /data/kvm /var/lib/libvirt/images

Stop virt-manager from prompting for password

 
    # groupadd libvirt
    # usermod -G libvirt oracle
    # vim /etc/polkit-1/rules.d/10.virt.rules
    polkit.addRule(function(action, subject) {
        if (action.id == "org.libvirt.unix.manage"
                && subject.local
                && subject.active
                && subject.isInGroup("libvirt")) {
            return polkit.Result.YES;
        }
    });
    # reboot

KVM-bridged Network Settings:

    sudo vim /etc/sysconfig/iptables
    -A FORWARD -m physdev --physdev-is-bridged -j ACCEPT
    sudo /etc/init.d/iptables restart
    sudo vim /usr/lib/sysctl.d/00-system.conf

        net.bridge.bridge-nf-call-ip6tables = 1
        net.bridge.bridge-nf-call-iptables = 1

    sudo sysctl -p

Auto Login

sudo vim /etc/gdm/custom.conf
[daemon]
AutomaticLoginEnable=True
AutomaticLogin=oracle # as username is oracle

Skype in RHEL 7 , sound fix:

sudo vim /usr/share/applications/skype.desktop
    Change line 4 to:

    Exec=env PULSE_LATENCY_MSEC=60 skype %U