Clone KVM Virtual Machine – How we use it in Linux

Need help to clone KVM Virtual Machine in Linux? We can help you.

Here at Bobcares, we assist our customers with several Linux queries as part of our Server Management Services.

Today, let us see how to do it using the

virt-clone

command.

 

What is virt-clone

virt-clone

is a command-line tool to clone existing virtual machine images that use

libvirt

as a hypervisor management library. First, it will copy the disk images of any existing virtual machine. Then it will define a new guest with an identical virtual hardware configuration.

Now let us proceed to learn how our Support Techs clone KVM Virtual Machine in Linux

 

Clone KVM Virtual Machine

Our Support Engineers suggest to follow the steps below to clone a VM on KVM:

Step 1: Make sure that the VM to clone is off.

We use the command below. Replace “asterisk-cloud” with the VM name.

$ sudo virsh shutdown asterisk-cloud

Then we run the below command to get a list of Virtual Machines

virsh

manages:

$ sudo virsh list –all
Id Name State
—————————————————-
– asterisk-cloud shut off
– instance-00000004 shut off

Step 2: Clone the Virtual Machine.

To clone

asterisk-cloud

virtual Machine to

kamailio-cloud

virtual machine, we run:

$ sudo virt-clone
–connect=qemu:///system
–original asterisk-cloud
–name kamailio-cloud
–file /var/lib/libvirt/images/kamailio-cloud.qcow2

Subsequently, the output will look like this:

Allocating ‘kamailio-cloud.qcow2’ | 8.0 GB 00:01:21
Clone ‘kamailio-cloud’ created successfully.

If we are connecting to a remote KVM/QEMU Host machine, we put the URL before /system.

It will look something like this:

$ sudo virt-clone
–connect=qemu://192.168.1.30/system
–original asterisk-cloud
–name kamailio-cloud
–file /var/lib/libvirt/images/kamailio-cloud.qcow2

• asterisk-cloud

  : Name of VM cloning from

• kamailio-cloud

  : Name given to resulting VM after cloning

• kamailio-cloud.qcow2

  : Image saved that

  kamailio-cloud

  boots from.

Then we check to confirm that

kamailio-cloud.qcow2

file is successfully stored in

/var/lib/libvirt/images

folder.

$ ls /var/lib/libvirt/images
total 6946188
-rw-r–r– 1 root root 3238789120 Mar 20 17:42 asterisk-cloud.qcow2
-rwxr-xr-x 1 qemu qemu 666894336 Mar 16 04:14 CentOS-7-x86_64-Minimal-1503-01.iso
-rw-r–r– 1 root root 3207331840 Mar 20 17:44 kamailio-cloud.qcow2

If we now run the command

virsh list –all

, we see cloned VM present in the list.

$ sudo virsh list –all
Id Name State
—————————————————-
– asterisk-cloud shut off
– instance-00000004 shut off
– kamailio-cloud shut off

Before starting the

kamailio-cloud

, change the channel source mode path from the original.

We do this by editing the file

/etc/libvirt/qemu/kamailio-cloud.xml

$ sudo vi /etc/libvirt/qemu/kamailio-cloud.xml

Then we look for the line below and change the original domain name to point to the new clone.

<channel type=’unix’>
<source mode=’bind’ path=’/var/lib/libvirt/qemu/channel/target/domain-kamailio-cloud/org.qemu.guest_agent.0’/>

Original was:

<channel type=’unix’>
<source mode=’bind’ path=’/var/lib/libvirt/qemu/channel/target/domain-asterisk-cloud/org.qemu.guest_agent.0’/>

Subsequently, to start the cloned virtual Machine, we type:

$ sudo virsh start kamailio-cloud –console

After logging in, we change

uuid

for the network interface. The one on CentOS 7.x Guest machine is eth0.

Similarly, to generate a new

uuid

for this interface, we type:

$ uuidgen eth0
29e28904-c8f6-4ac0-93f0-d5d2cedb8555

Original eth0 configuration file from asterisk-cloud VM look like below:

TYPE=Ethernet
BOOTPROTO=dhcp
DEFROUTE=yes
IPV4_FAILURE_FATAL=no
IPV6INIT=yes
IPV6_AUTOCONF=yes
IPV6_DEFROUTE=yes
IPV6_FAILURE_FATAL=no
NAME=eth0
UUID=230e87b1-f847-4cab-86b9-df4268a0a0a3
DEVICE=eth0
ONBOOT=yes
PEERDNS=yes
PEERROUTES=yes
IPV6_PEERDNS=yes
IPV6_PEERROUTES=yes

Then we change

uuid

replacing old with generated one:

$ sudo vim /etc/sysconfig/network-scripts/ifcfg-eth0

On the other hand, we modify the below configurations to fit use cases.

TYPE=Ethernet
TYPE=Ethernet
BOOTPROTO=dhcp
DEFROUTE=yes
IPV4_FAILURE_FATAL=no
IPV6INIT=yes
IPV6_AUTOCONF=yes
IPV6_DEFROUTE=yes
IPV6_FAILURE_FATAL=no
NAME=eth0
UUID=29e28904-c8f6-4ac0-93f0-d5d2cedb8555
DEVICE=eth0
ONBOOT=yes
PEERDNS=yes
PEERROUTES=yes
IPV6_PEERDNS=yes
IPV6_PEERROUTES=yes

Then we restart network service:

$ sudo service network restart
$ sudo systemctl restart network.service

[Find it hard to clone KVM? We’d be happy to assist you]

 

Conclusion

To conclude, we learned how to use the

virt-clone

command which provides a number of options to clone a KVM VM. Today, we saw an effective method employed by our Support Techs in this regard.