introduction to virtualization, virsh and virt-manager
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TRANSCRIPT
Introduction to Virtualization, Virsh Commands and Virt-Manager
Chin Pin Chang
04/07/2014
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Outline• Virtualization
– Introduction– Types of Virtualization – KVM– Practice: KVM Installation
• Virsh Commands– Introduction– Practice: 3 Units
• Virt-Manager • Conclusion• References
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3
Virtualization Introduction
• Virtualization is a broad term that refers to the abstraction of computer physical resources such as servers, network, memory and storage
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Virtualization Introduction (cont.)
• Without Virtualization • With Virtualization
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Why Virtualization• Resource sharing• High utilization of resource• Reduce the number of physical servers• Ability to bring up new server quickly• Easy maintenance and monitoring
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Types of Virtualization• Server Virtualization
– Full virtualization, Paravirtualization, Hardware-assisted virtualization
• Application Virtualization• Desktop Virtualization• Presentation Virtualization• Network Virtualization• Storage Virtualization
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KVM Introduction• KVM (Kernel-based Virtual Machine)
– A Linux kernel module that turns Linux into a hypervisor– Full virtualization
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Install KVM
• Check that your CPU supports hardware virtualization
– 0 indicates that your CPU doesn’t support hardware virtualization
– 1 or more indicates that it supports hardware virtualization
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Install KVM (cont.)
• Check BIOS– Support
– Not support
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Install KVM (cont.)
• Install necessary packages– qemu-kvm– libvirt-bin – ubuntu-vm-builder – bridge-utils
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Add Users to Libvirtd and KVM Groups
• Add user "username" to libvirtd
• Add user " username" to KVM
• Need to re-login
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Verify Installation
• Check groups
• Verify Installation
• Change the device's group
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Install Virt-manager
• Install virt-manager
• Start virt-manager
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Step 1 - Create new virtual machine
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Step 2 – Locate install media
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Step 3 – Specify CPU and Memory
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Step 4 – Specify Storage
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Step 5 – Specify Network
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Install Ubuntu Server
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Virsh Introduction
• Virsh is a command line interface tool for managing VM and the hypervisor
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Virsh Introduction (cont.)
• Virsh Commands Classification– Domain management commands – Domain monitoring commands– Host and hypervisor commands– Interface commands– Network filter commands– Virtual networking commands– Node device commands– Secrets commands– Domain snapshot commands– Storage pool commands– Storage volume commands– Virsh commands
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Virsh Commands
Unit 1Domain Management
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Introduction
• Domain management– Is used to manage VM– Major commands: define, start, destroy, suspend,
resume and so on
How to use virsh
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define
Item Content
Description Define, but don't start, a guest domain from an XML file
Input 1. XML file
Example # define vm1.xml
Response Domain vm1 defined from vm1.xml
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Define a VM
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XML for VM
<domain type='kvm' xmlns:qemu='http://libvirt.org/schemas/domain/qemu/1.0'> <name>vm1</name> <uuid>b7cb10e2-c6af-a328-ad75-3e09747f0564</uuid> <memory>524288</memory> <currentMemory>524288</currentMemory> <vcpu>1</vcpu> <os> <type arch='armv7l' machine='vexpress-a15'>hvm</type> <kernel>/root/zImage</kernel> <cmdline>earlyprintk=ttyAMA0 console=ttyAMA0 mem=512M root=/dev/vda rw ip=192.168.20.56::192.168.20.101:vm1:eth0:off --no-log</cmdline> <dtb>/root/guest-vexpress.dtb</dtb> </os> <features> <acpi/> <pae/> </features><!-- <cpu> <model>cortex-a15</model> </cpu> -->
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XML for VM (cont.)
<clock offset='utc'/> <on_poweroff>destroy</on_poweroff> <on_reboot>restart</on_reboot> <on_crash>destroy</on_crash> <devices> <emulator>/usr/bin/qemu-system-arm</emulator> <disk type='file' device='disk'> <driver name='qemu' type='raw' cache='none'/> <source file='/root/nfs/ubuntu1G.img'/> <target dev='vda' bus='virtio'/> </disk> <interface type='bridge'> <source bridge='virbr0'/> <mac address='52:54:00:12:34:55'/> <model type='virtio'/> </interface> <console type='pty'/> </devices></domain>
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XML parameters
• name– Virtual machine name
• uuid– A globally unique identifier for the virtual machine
• current memory– The actual allocation of memory for the VM
• type– The type of operating system in the virtual machine
• kernel– The fully-qualified path to the kernel image in the host OS
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XML parameters (cont.)
• cmdline– The arguments to be passed to the kernel at boot time
• dtb– The fully-qualified path to the device tree binary image in
the host OS• emulator
– The fully qualified path to the device model emulator binary• disk
– The main container for describing disks• source file
– The resource on the host that is being accessed in the guest
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XML parameters (cont.)
• target– The source can be accessed in the guest
• interface type– A network interface visible to the guest
• source bridge– The interface of the network
• mac address– The address of the network
• model type– The model of emulated network interface
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start
Item Content
Description Start a guest domain, either from the last managed save state, or via a fresh boot if no managed save state is present
Input 1.domain
Example # start vm1
Response Domain vm1 started
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Start VM
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domid
Item Content
Description Convert a domain name or UUID to domain id
Input 1. domain
Example # domid vm1
Response 1
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domname
Item Content
Description Convert a guest domain id or UUID to guest domain name
Input 1. domain
Example # domname 1
Response vm1
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domuuid
Item Content
Description Convert a guest domain name or id to guest domain UUID
Input 1. domain
Example # domuuid vm1
Response b7cb10e2-c6af-a328-ad75-3e09747f0564
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VM Information
• The domain ID
• The domain name
• The domain uuid
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autostart
Item Content
Description Enable and disable the automatic starting of a guest domain when the libvirt daemon starts
Input 1. domain
Example # autostart vm1
Response Domain vm1 marked as autostarted
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Auto start VM
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list
Item Content
Description Returns a list of guest domains
Input N/A
Example # list
Response virsh # list Id Name State ---------------------------------------------------- 1 vm1 running
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List VM
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console
Item Content
Description Connect the virtual serial console for the guest
Input 1. domain
Example # console vm1
Response Connected to domain vm1 Escape character is ^]
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Connect to VM
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Connect to VM (cont.)
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• Launch Apache service
• Check Apache service
Connect to VM (cont.)
• Check the IP of the VM
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Connect to VM (cont.)
• Check /var/www/index.html
• Web page
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suspend
Item Content
Description Suspend a running guest domain
Input 1.domain
Example # suspend vm1
Response Domain vm1 suspended
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Suspend VM
• Web page
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resume
Item Content
Description Resume a guest domain
Input 1.domain
Example # resume vm1
Response Domain vm1 resumed
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Resume VM
• Web page
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save
Item Content
Description Save the running state of a guest domain to a file
Input 1.domain 2.file
Example # save vm1 image
Response Domain vm1 saved to image
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restore
Item Content
Description Restore a guest domain
Input 1.file
Example # restore image
Response Domain restored from image
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Save and Restore scenario
S0
Save the VM
Restore the VM
Start the VM
Modify index.htm
S0S2S1
Step 4Step 3Step 2Step 1
Step 1
• Save the VM
• The saved file
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Step 2 and 3
• Start the VM• Modify /var/www/index.html
• Web page
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Step 4
• Restore the VM
• Web page
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destroy
Item Content
Description Immediately terminates a running guest domain, releasing any resources in use by it
Input 1.domain
Example # destroy vm1
Response Domain vm1 destroyed
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Destroy VM
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The memory information of the host
• Before destroying the VM
• After destroying the VM
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undefine
Item Content
Description Remove the configuration for an inactive guest domain
Input 1.domain
Example # undefine vm1
Response Domain vm1 has been undefined
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Undefine VM
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Virsh Commands
Unit 2Interface Management and
Network Management
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Introduction
• Interface management– To create an interface on the host for VM
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iface-define
Item Content
Description Define a physical host network interface
Input 1. XML file
Example # iface-define br1.xml
Response Interface br1 defined from br1.xml
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Define an interface
• Interface br1
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XML for Interface<interface type='bridge' name='br1'> <start mode='onboot'/> <bridge> <interface type='vlan' name='bond0.1'> <vlan tag='1'> <interface name='bond1'/> </vlan> </interface> </bridge> </interface>
XML parameters
• interface type– Network interface type
• interface name– The name of interface
• bridge type – The type of bridge
• vlan tag– Use to tag of the vlan
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iface-start
Item Content
Description Enables and starts a physical host network interface
Input 1. interface
Example # iface-start br1
Response Interface br1 started
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Start interface
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iface-name
Item Content
Description Returns the physical host interface name for a MAC address
Input 1. interface(MAC address)
Example # iface-name 3a:a0:42:19:ca:b2
Response br1
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iface-mac
Item Content
Description Returns the MAC address for a physical host network interface
Input 1. interface
Example # iface-mac br1
Response 3a:a0:42:19:ca:b2
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Interface Information
• The interface name
• The interface mac
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iface-destroy
Item Content
Description Shut down and disable a physical host network interface
Input 1. interface
Example # iface-destroy br1
Response Interface br1 destroyed
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Destroy interface
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iface-undefine
Item Content
Description Removes the configuration information for a physical host network interface
Input 1. interface
Example # iface-undefine br1
Response Interface br1 undefined
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Undefine interface
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Introduction
• Network management– Libvirt has the capability to define virtual networks
which can then be used by domains and linked to actual network devices
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net-define
Item Content
Description Adds a new permanent virtual network from an XML file, without starting it
Input 1. file
Example # net-define vlan1.xml
Response Network vlan1 defined from vlan1.xml
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Define network
• Network vlan1
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XML for Network<network > <name>vlan1</name> <forward mode='bridge'/> <bridge name='br1' /></network>
XML parameters
• name– Virtual network name
• forward mode– Inclusion of the forward element indicates that the virtual
network is to be connected to the physical LAN
• bridge name– The name of a bridge device
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net-start
Item Content
Description Starts a (previously defined) inactive virtual network
Input 1. network
Example # net-start vlan1
Response Network vlan1 started
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Start network
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net-autostart
Item Content
Description Enable or disable the automatic starting of a virtual network, when the libvirt daemon starts
Input 1. network
Example # net-autostart vlan1
Response Network vlan1 marked as autostarted
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Auto start network
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net-infoItem Content
Description Displays basic information for a virtual network
Input 1. network
Example # net-info vlan1
Response
Name vlan1 UUID f1f1cd7e-b623-4d7e-94c8-2047da1decef Active: yes Persistent: yes Autostart: yes Bridge: br1
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Network Information
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net-name
Item Content
Description When given a network UUID, returns its corresponding network name
Input 1. network
Example # net-name f1f1cd7e-b623-4d7e-94c8-2047da1decef
Response vlan1
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net-uuid
Item Content
Description When given a network name, returns its corresponding UUID
Input 1. network
Example # net-uuid vlan1
Response f1f1cd7e-b623-4d7e-94c8-2047da1decef
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Network Information
• The network name
• The network uuid
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net-destroy
Item Content
Description Shuts down a running virtual network
Input 1. network
Example # net-destroy vlan1
Response Network vlan1 destroyed
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Destroy network
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net-undefine
Item Content
Description Removes an inactive virtual network from the libvirt configuration
Input 1. network
Example # net-undefine vlan1
Response Network vlan1 has been undefined
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Undefine network
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Interface and Network scenario
Hostvirbr0
br1 br2
VM1 VM2 VM3
IP: 192.168.1.101 192.168.1.102 192.168.1.103
vlan1
vlan2
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Example
• Define the interfaces br1 and br2
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XML for host
• br1.xml<interface type='bridge' name='br1'> <start mode='onboot'/> <bridge> <interface type='vlan' name='bond0.1'> <vlan tag='1'> <interface name='bond1'/> </vlan> </interface> </bridge> </interface>
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XML for host (cont.)
• br2.xml<interface type='bridge' name='br2'> <start mode='onboot'/> <bridge> <interface type='vlan' name='bond0.2'> <vlan tag=‘2'> <interface name='bond2'/> </vlan> </interface> </bridge> </interface>
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XML for VM• Modify VM1.xml
• Modify VM2.xml
• Modify VM3.xml
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Define VM
• Define VM1, VM2 and VM3
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Start VM
• Start VM1, VM2 and VM3
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Start interface
• Start interface br1 and br2
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Connect to VM
• Assign IP (192.168.0.101) to VM1
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Connect to VM (cont.)
• Assign IP (192.168.0.102) to VM2
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Connect to VM (cont.)
• Assign IP (192.168.0.103) to VM3
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Result
• VM1 ping VM2
• VM1 ping VM3
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Result (cont.)
• VM3 ping VM1
• VM3 ping VM2
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Virsh Commands
Unit 3Snapshot and Migrate
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Introduction
• Snapshot– Snapshots take the disk, memory, and device state
of a VM at a point-of-time, and save it for future use
• --disk-only– The snapshot will only include disk state
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Snapshot scenario
Create a folder and
modify index.htm
Start the VM
Restart the VM
Revert the
snapshot
Step 4Step 3Step 2Step 1
S0 S3S2S1 S1
Step 5
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snapshot-create
Item Content
Description Create a snapshot (disk and RAM) from XML
Input 1. domain 2. xml
Example # snapshot-create vm1 snaptest.xml
Response Domain snapshot snaptest created from 'snaptest.xml'
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• Start VM• Take a snapshot
Create a snapshot for VM
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Create a folder in VM
• Start VM• Create a folder "test"
Launch Apache service
• Check /var/www/index.html
• Web page
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Launch Apache service (cont.)
• Modify the /var/www/index.html
• Web page
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snapshot-revert
Item Content
Description Reverts a domain to a given snapshot
Input 1. domain 2. snapshotname
Example # snapshot-revert vm1 snaptest
Response N/A
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Revert snapshot
• Folder
• Web page
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snapshot-delete
Item Content
Description Removes a snapshot, and all of it's children, from a domain
Input 1. domain 2. snapshotname
Example # snapshot-delete --domain vm1 snaptest --metadata
Response Domain snapshot snaptest deleted
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Delete snapshot
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Introduction
• Migrate– Migration is the process of moving a virtual
machine from one host or storage location to another
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Migration
Source
VMDownload
a file
Destination
VMDownload
a file
Migration
Network
IP: 192.92.26.120 IP: 192.92.26.108
NFS/Data/image
VMimage
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Set up NFS server for images
• Install NFS server packages – nfs-common– nfs-kernel-server
• Set shared path and permission
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Set up NFS server for images (cont.)
• Start NFS server
• Check NFS path
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Set up NFS client – hypervisor
• Install NFS client packages – nfs-common
• Mount image
• Check
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Set up NFS client – hypervisor (cont.)
• Restart NFS server
• Check image on client
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migrate
Item Content
Description Migrates a guest domain to another host
Input 1.domain 2.dest uri
Example # migrate vm1 qemu+ssh://140.92.26.108/system
Response pass
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Start VM
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Download a file to VM
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Migrate VM to destination host
• Source host
The URI of the destination host
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After migration
• Destination host
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Verify the file
• The file size
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Virt-manager Introduction• The virt-manager (Virtual Machine Manager)
application is a graphic user interface for managing virtual machines through libvirt
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Main window
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Connection window
Define VM
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Start VM
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Connect to VM
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Verify connection
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• Virt-manager
Suspend VM
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Resume VM
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Save VM
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Save VM (cont.)
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Restore VM
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Clone VM
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Check CPU usage of VM
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Destroy VM
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Delete VM
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Conclusion
• Virtualization– High utilization of physical resource
• Virsh – The main interface for managing virtualization
environment through Libvirt• Virt-manager
– Graphic user interface for managing virtualization environment through Libvirt
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References• http://libvirt.org/• http://en.wikipedia.org/wiki/Virtualization• http://en.wikipedia.org/wiki/Kernel-based_Virtual_Machine • http://www.slideshare.net/trupti242/virtuallization-
questions#• https://access.redhat.com/site/documentation/en-US/
Red_Hat_Enterprise_Linux/• http://trac.nchc.org.tw/cloud• https://help.ubuntu.com/community/KVM/Installation• http://www.ubuntu-tw.org/modules/tinyd0/