KVM Command Line¶

"virsh" shell for KVM.

List All Domain on KVM¶

virsh list --all

Define or use .xml¶

virsh define <xyz.xml>

Start KVM¶

virsh start <xyz>

Edit Guest .xml¶

virsh edit xyz

List VNC Information¶

virsh vncdisplay xyz

Domain Format in KVM

Test your bootable USB on kvm¶

In order to test your USB using KVM use following command.

qemu-kvm -hdb <device>

In my case device was "/dev/sdb".

Converting Existing Image¶

Converting VMWARE image for KVM¶

use following command.

qemu-img convert own_Cloud.vmdk -O qcow2 ownCloud.qcow

Converting .ova to KVM image¶

what is ova - Open Virtualization Format

Download - Open Virtualization Format Tool

Install it, which give you command "ovftool".

ovftool -tt=vmx Amazon-EC2-VM-Import-Connector.ova amazon_kvm

converting .ova is just easy
some times ovftool failing

If Above does not work just do

tar -xvf Amazon-EC2-VM-Import-Connector.ova

Now follow Converting VMWARE image for KVM

Create New KVM Guest using existing Image¶

virt-install --name=own_cloud --arch=x86_64 \
--vcpus=1 --ram=512 --os-type=linux --os-variant=sles11 \
--hvm --connect=qemu:///system --network bridge:br0 \
--import --disk path=/home/vmware/ownCloud_in_a_box-1.0.4/ownCloud.qcow \
--accelerate --vnc --noautoconsole --keymap=us

Backup¶

Creating snapshot of Machine¶

NOTE :
- This will turn off your Guest.
- it will create snapshot in current working directory.
- Use virsh pwd to check your current working directory.

virsh save <Domain Name> <fileName>

Quick Command Ref.¶

help     Prints basic help information.
list     Lists all guests.
dumpxml  Outputs the XML configuration file for the guest.
create   Creates a guest from an XML configuration file and starts the new guest.
start    Starts an inactive guest.
destroy  Forces a guest to stop.
define   Outputs an XML configuration file for a guest.
domid    Displays the guest's ID.
domuuid  Displays the guest's UUID.
dominfo  Displays guest information.
domname  Displays the guest's name.
domstate     Displays the state of a guest.
quit     Quits the interactive terminal.
reboot   Reboots a guest.
restore  Restores a previously saved guest stored in a file.
resume   Resumes a paused guest.
save     Save the present state of a guest to a file.
shutdown     Gracefully shuts down a guest.
suspend  Pauses a guest.
undefine     Deletes all files associated with a guest.
migrate  Migrates a guest to another host.

setmem   Sets the allocated memory for a guest.
setmaxmem    Sets maximum memory limit for the hypervisor.
setvcpus     Changes number of virtual CPUs assigned to a guest.
vcpuinfo     Displays virtual CPU information about a guest.
vcpupin  Controls the virtual CPU affinity of a guest.
domblkstat   Displays block device statistics for a running guest.
domifstat    Displays network interface statistics for a running guest.
attach-device    Attach a device to a guest, using a device definition in an XML file.
attach-disk  Attaches a new disk device to a guest.
attach-interface     Attaches a new network interface to a guest.
detach-device    Detach a device from a guest, takes the same kind of XML descriptions as command attach-device.
detach-disk  Detach a disk device from a guest.
detach-interface     Detach a network interface from a guest.

FU Commands¶

Create Disk¶

create disk of size 10G File: for dynamic allocation

qemu-img create -f raw vdisk.img 10G

OR File: preallowcation

dd if=/dev/zero of=vdisk.img bs=1G count=0 seek=[NUMBER_OF_GB]

How to allow network access to KVM Guest¶

Modify guest.xml file and listen variable. File: vi /etc/libvirt/qemu/Archlinux.xml

<graphics type='vnc' port='-1' autoport='yes' listen='192.168.1.4' passwd='testing1'/>

Extract folder from KVM Guest Image¶

This appears to be the far easy solution than I thought.
Link to official Document

For RHEL you require the following packages installed. - libguestfs-tools - libguestfs-xfs # if guest filesystem is XFS.

mkdir test
virt-copy-out -a machine2.qcow2 /metadata/testing/users test/

Image File explorer¶

This is a simple way to extract or access files.
Scan and assign the dev node.

losetup --partscan --find --show sdcard.img

List all the block devices, including newly scanned.

lsblk --fs

Mounting the file system

mount /dev/loop0p2 /mnt/sdcard

Once unmounted remove the lo drive.

losetup --detach-all