KVM22p2: Nested KVM LAB CentOS7

# In The Name Of Allah .
# -- --- ---- -- ----- -
# Sat Aug  4 17:54:17 2018
# Written By : zer0err0r .
# ======= == = ========= =

# Vanilla KVM CheatSheet Using CentOS7minimal With Ethernet Connection .
  = a Remote [virt-manager] will be used to manage VMs if necessary .
  = SELinux is enforcing and FirewallD is enabled .
  = directory_based_pool will be used and its target will be [/home/zer0err0r/kvm/] .
  = Remember that [Pool > Volume > VM] .

  
  # Before We Start :
    $ sudo -i                             # To configure as root .
    $ egrep '(vmx|svm)' /proc/cpuinfo     # To check if your CPU support virtualization or not .
    $ lsmod | grep kvm                    # To check if kvm module is loaded or not .
    $ yum install qemu-kvm qemu-img libvirt libvirt-client libvirt-python virt-install virt-top libguestfs-tools 
    $ usermod -a -G libvirt zer0err0r     
    $ systemctl enable --now libvirtd 
    $ exit                                # To exit root .
    = Do [ssh-keygen] then [ssh-copy-id] to set a SSH passwordless authentication .
    = Keep using or add an alias for [--connect qemu:///system] when using normal user .
    = Use [--connect 'qemu+ssh://USER@IP/system'] for remote hypervisors .
    $ exit
    
  
  # Creating network bridge :
    $ sudo -i 
    $ echo 'BRIDGE=br0' >> /etc/sysconfig/network-scripts/ifcfg-eth0
    $ vim /etc/sysconfig/network-scripts/ifcfg-br0
      DEVICE="br0"
      BOOTPROTO=static
      IPADDR=192.168.100.100
      NETMASK=255.255.255.0
      NETWORK=192.168.100.0
      GATEWAY=192.168.100.1
      DNS1=8.8.8.8
      IPV6INIT="yes"
      IPV6_AUTOCONF="yes"
      ONBOOT="yes"
      TYPE="Bridge"     # First letter is an upper-case letter .
      DELAY="0"
    $ systemctl restart NetworkManager
    $ echo 'net.ipv4.ip_forward = 1' >> /etc/sysctl.conf
    $ sysctl -p /etc/sysctl.conf
    $ exit

  
  # Creating a pool :
    $ mkdir /home/zer0err0r/kvm
    $ chmod o+x /home/zer0err0r
    $ sudo yum -y install policycoreutils-python
    $ sudo semanage fcontext --add -t virt_image_t '/home/zer0err0r/kvm(/.*)?'
    $ sudo restorecon -R -v /home/zer0err0r/kvm
    $ virsh pool-list --all         # To verify current pools .
    $ virsh pool-define-as my_pool dir - - - - /home/zer0err0r/kvm
    $ virsh pool-build my_pool      # To build the pool .
    $ virsh pool-start my_pool
    $ virsh pool-autostart my_pool 
    $ virsh pool-list --all         # To verify current pools .

  
  # Creating Volume :
    $ virsh vol-create-as my_pool disk_1.qcow2 15G --format qcow2       # To create the pool .
    $ virsh vol-info --pool my_pool vm1_disk1

  
  # Create the VM :
    $ virt-install --network bridge:br0 --name vm1 --ram=1024 --vcpus=1 --disk "vol=my_pool/vm1_disk1.qcow2" --graphics vnc \
      --location /home/zer0err0r/kvm/cd.iso --extra-args="console=tty0 console=ttyS0,115200" --os-variant centos7.0

    # For windows :
      $ virt-install --network bridge:br0 --name vm1 --ram=1024 --vcpus=1 --disk "vol=my_pool/vm1_disk1.qcow2" --graphics vnc \
        --cdrom /home/zer0err0r/kvm/cd.iso --os-variant win2k8 

  
  # Connect to the VM :
    = Either you use a remote [virt-manager, virt-viewer] to install it .
    = Or you can use kickstart to install the system and a cli console .
    = I prefer using [virt-manager] or [virt-viewer] from any other machine if you created the VM with vnc support, So :
      $ virt-viewer --connect 'qemu+ssh://zer0err0r@vbox/system'

  
  # Clone the VM :
    $ virsh suspend vm1   # vm1 should be stopped .
    $ virt-clone --original vm1 --name vm1-clone --file /home/zer0err0r/kvm/vm1-clone.img
    = If vm1 uses a static network addressing, Then change the clone address and then resume the original .
    $ virt-clone --auto-clone --original vm1  # To drop using [--disk, --name] .
    = Dont warry, The cloned VM volume will be inside the same pool dir .
  
  
  # Managing VMs :
    $ virsh list --all                  # To list available VMs .
    $ virsh dominfo vm1                 # To show VM informations .
    $ virt-top                          # Like [top] command for VMs .
    $ virt-df vm1                       # Show VM disk partitions, It may take a few moments .
    $ virsh shutdown vm1                # Stop a VM .
    $ virsh destroy vm1                 # Force stop the VM .
    $ virsh start vm1                   # Start VM .
    $ virsh reboot vm1                  # Restart a VM .
    $ virsh autostart vm1               # Mark VM for autostart, So VM will start automatically after host reboots .
    $ virsh autostart --disable vm1     # Mark VM for manual start .
    $ virsh list --all --autostart      # Show autostarted VMs .

  
  # Deleting VMs :
    $ virsh list --all      # To view running VMs .
    $ virsh shutdown vm1 || virsh destroy vm1   # To stop the VMs .
    $ virsh undefine vm1    # To undefine the VM configurations .

    # Delete the Volume :
      $ virsh vol-list my_pool
      $ virsh vol-delete --pool my_pool vm1_disk1

    # Delete the pool if needed to :
      $ virsh pool-list
      $ virsh pool-destroy my_pool
      $ virsh pool-undefine my_pool

# ===== == ==== ======== =
# Peace Be Up0n Muhammed .