Kernel-based Virtual Machine (KVM) is virtualization software for CentOS 7. KVM turn your server into a hypervisor. This blog shows how to setup and manage a virtualized environment with KVM in CentOS 7 on GCP.
Environment :
- Google cloud environment (GCP)
- Nested VM running on GCP
- Centos 7
Create GCP nested VM image from Google cloud CLI console:
gcloud compute disks create disk1 \
--image-project centos-cloud \
--image-family centos-7 --zone australia-southeast1-a
gcloud compute images create nested-vm-image \
--source-disk disk1 \
--source-disk-zone australia-southeast1-a \
--licenses "https://www.googleapis.com/compute/v1/projects/vm-options/global/licenses/enable-vmx"
Verify Virtualization enable on KVM server:
# lscpu | grep Virtualization
Install the required packages on KVM server:
# yum install virt-install qemu-kvm libvirt \
libvirt-python libguestfs-tools virt-manager wget -y
Enable and start the services :
# systemctl enable libvirtd
# systemctl start libvirtd
# systemctl status libvirtd
Update qemu to latest version :
# yum install centos-release-qemu-ev -y
Check kernal modules for KVM :
# lsmod | grep -i kvm
kvm_intel 188683 0
kvm 621392 1 kvm_intel
irqbypass 13503 1 kvm
Configure bridged networking:
# brctl show
bridge name bridge id STP enabled interfaces
virbr0 8000.525400449dfa yes virbr0-nic
# virsh net-list
Name State Autostart Persistent
----------------------------------------------------------
default active yes yes
# vi /etc/sysconfig/network-scripts/ifcfg-eth0
add line ==> BRIDGE="br0"
Create file ifcfg-br0 on /etc/sysconfig/network-scripts
DEVICE="br0"
BOOTPROTO="dhcp"
IPV6INIT="yes"
IPV6_AUTOCONF="yes"
ONBOOT="yes"
TYPE="Bridge"
DELAY="0"
# systemctl restart NetworkManager
# brctl show
bridge name bridge id STP enabled interfaces
br0 8000.000000000000 no
virbr0 8000.525400449dfa yes virbr0-nic
Download the iso image :
# cd /var/lib/libvirt/boot/
# wget https://mirrors.edge.kernel.org/centos/7.6.1810/isos/x86_64/CentOS-7-x86_64-Minimal-1810.iso
# wget https://mirrors.edge.kernel.org/centos/7.6.1810/isos/x86_64/sha256sum.txt
# sha256sum -c sha256sum.txt
Create guest virtual machine on KVM server:
# virt-install --name=centos7vm \
--ram=1024 \
--vcpus=1 \
--location=/var/lib/libvirt/boot/CentOS-7-x86_64-Minimal-1810.iso \
--os-type=linux --os-variant=centos7.0 \
--network=bridge=virbr0,model=virtio \
--disk path=/var/lib/libvirt/images/centos7.qcow2,size=10,bus=virtio,format=qcow2 \
--graphics none --console pty,target_type=serial \
--extra-args 'console=ttyS0,115200n8 serial'
Verify guest virtual machine :
# virsh net-list
Name State Autostart Persistent
----------------------------------------------------------
default active yes yes
# virsh domiflist centos7vm
Interface Type Source Model MAC
-------------------------------------------------------
vnet0 bridge virbr0 virtio 52:54:00:93:a5:23
# virsh net-dhcp-leases default
Expiry Time MAC address Protocol IP address Hostname Client ID or DUID
-------------------------------------------------------------------------------------------------------------------
2019-09-20 04:39:43 52:54:00:93:a5:23 ipv4 192.168.122.46/24 centos7vm -
# virsh console centos7vm
Connected to domain centos7vm
Escape character is ^]
Ctr + ] ( to exit from guest vm console)
# virsh list --all
Id Name State
----------------------------------------------------
2 centos7vm running
# virsh dominfo centos7vm
Id: 2
Name: centos7vm
UUID: 217550ae-cdcc-4c96-a222-fc122a7126c8
OS Type: hvm
State: running
CPU(s): 1
CPU time: 33.7s
Max memory: 1048576 KiB
Used memory: 1048576 KiB
Persistent: yes
Autostart: disable
Managed save: no
Security model: selinux
Security DOI: 0
Security label: system_u:system_r:svirt_t:s0:c351,c948 (enforcing)
