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About KVM
Advantages of Virtualization
Using KVM
Use Cases
Linux Kernel-based Virtual Machine
Features of KVM and how to use it in SOHO/SME
Sven Vermeulen
HCC Vlaanderen
2010/10/04 - Mechelen(Tisselt)
Summary
About KVM
Advantages of Virtualization
Outline
1
About KVM
What is KVM
Using KVM
Use Cases
Summary
About KVM
Advantages of Virtualization
Outline
1
About KVM
What is KVM
2
Advantages of Virtualization
At Home
At Work (SO)
At Work (ME)
Using KVM
Use Cases
Summary
About KVM
Advantages of Virtualization
Outline
1
About KVM
What is KVM
2
Advantages of Virtualization
At Home
At Work (SO)
At Work (ME)
3
Using KVM
Plain Qemu
Using libvirt
Using KVM
Use Cases
Summary
About KVM
Advantages of Virtualization
Outline
1
About KVM
What is KVM
2
Advantages of Virtualization
At Home
At Work (SO)
At Work (ME)
3
Using KVM
Plain Qemu
Using libvirt
4
Use Cases
Example Use Cases
Using KVM
Use Cases
Summary
About KVM
Advantages of Virtualization
What is KVM
Outline
1
About KVM
What is KVM
2
Advantages of Virtualization
At Home
At Work (SO)
At Work (ME)
3
Using KVM
Plain Qemu
Using libvirt
4
Use Cases
Example Use Cases
Using KVM
Use Cases
Summary
About KVM
Advantages of Virtualization
Using KVM
What is KVM
Linux Kernel-based Virtual Machine
Built on the Linux operating system.
Use Cases
Summary
About KVM
Advantages of Virtualization
Using KVM
What is KVM
Linux Kernel-based Virtual Machine
Built on the Linux operating system.
Is heavily relying on kernel-based features
Use Cases
Summary
About KVM
Advantages of Virtualization
Using KVM
Use Cases
What is KVM
Linux Kernel-based Virtual Machine
Built on the Linux operating system.
Is heavily relying on kernel-based features
Requires x86 hardware with virtualization extensions
Intel VT (vmx)
AMD-V (svm)
and only provides virtual x86 environments
Summary
About KVM
Advantages of Virtualization
Using KVM
Use Cases
What is KVM
Uses QEMU As “Runtime”
http://wiki.qemu.org
Generic, Open Source machine emulator and virtualizer
Can use virtualization APIs (“hypervisor”)...
Summary
About KVM
Advantages of Virtualization
Using KVM
Use Cases
What is KVM
Uses QEMU As “Runtime”
http://wiki.qemu.org
Generic, Open Source machine emulator and virtualizer
Can use virtualization APIs (“hypervisor”)...
but also supports full software emulation
Summary
About KVM
Advantages of Virtualization
Using KVM
Use Cases
What is KVM
Uses QEMU As “Runtime”
http://wiki.qemu.org
Generic, Open Source machine emulator and virtualizer
Can use virtualization APIs (“hypervisor”)...
but also supports full software emulation
Features
Pass-through hardware access (esp. useful for USB)
Summary
About KVM
Advantages of Virtualization
Using KVM
Use Cases
What is KVM
Uses QEMU As “Runtime”
http://wiki.qemu.org
Generic, Open Source machine emulator and virtualizer
Can use virtualization APIs (“hypervisor”)...
but also supports full software emulation
Features
Pass-through hardware access (esp. useful for USB)
raw disk image, copy-on-write images, native disk storage
and VMWare images
Summary
About KVM
Advantages of Virtualization
Using KVM
Use Cases
What is KVM
Uses QEMU As “Runtime”
http://wiki.qemu.org
Generic, Open Source machine emulator and virtualizer
Can use virtualization APIs (“hypervisor”)...
but also supports full software emulation
Features
Pass-through hardware access (esp. useful for USB)
raw disk image, copy-on-write images, native disk storage
and VMWare images
multiple CPUs (up to 255)
Summary
About KVM
Advantages of Virtualization
Using KVM
Use Cases
What is KVM
Uses QEMU As “Runtime”
http://wiki.qemu.org
Generic, Open Source machine emulator and virtualizer
Can use virtualization APIs (“hypervisor”)...
but also supports full software emulation
Features
Pass-through hardware access (esp. useful for USB)
raw disk image, copy-on-write images, native disk storage
and VMWare images
multiple CPUs (up to 255)
virtual networking support (incl. access to real network)
Summary
About KVM
Advantages of Virtualization
Using KVM
Use Cases
Summary
What is KVM
And KVM as “hypervisor”
Uses Linux features:
Is able to swap out running images (just regular processes)
About KVM
Advantages of Virtualization
Using KVM
Use Cases
Summary
What is KVM
And KVM as “hypervisor”
Uses Linux features:
Is able to swap out running images (just regular processes)
Can optimize memory usage using Kernel Sharedpage
Merging and a balloon driver
About KVM
Advantages of Virtualization
Using KVM
Use Cases
Summary
What is KVM
And KVM as “hypervisor”
Uses Linux features:
Is able to swap out running images (just regular processes)
Can optimize memory usage using Kernel Sharedpage
Merging and a balloon driver
Supports resource management using control groups
About KVM
Advantages of Virtualization
Using KVM
Use Cases
Summary
What is KVM
And KVM as “hypervisor”
Uses Linux features:
Is able to swap out running images (just regular processes)
Can optimize memory usage using Kernel Sharedpage
Merging and a balloon driver
Supports resource management using control groups
Supports paravirtualized PCI, networking and serial access
About KVM
Advantages of Virtualization
Using KVM
Use Cases
Summary
What is KVM
And KVM as “hypervisor”
Uses Linux features:
Is able to swap out running images (just regular processes)
Can optimize memory usage using Kernel Sharedpage
Merging and a balloon driver
Supports resource management using control groups
Supports paravirtualized PCI, networking and serial access
Runtime environments run as user processes
but
About KVM
Advantages of Virtualization
Using KVM
Use Cases
Summary
What is KVM
And KVM as “hypervisor”
Uses Linux features:
Is able to swap out running images (just regular processes)
Can optimize memory usage using Kernel Sharedpage
Merging and a balloon driver
Supports resource management using control groups
Supports paravirtualized PCI, networking and serial access
Runtime environments run as user processes
but
is definitely not limited to running Linux guests
FreeBSD, Windows (3.11 - 7), MacOS, Android,
ChromeOS, ...
About KVM
Advantages of Virtualization
Using KVM
Use Cases
What is KVM
Development
KVM is part of Linux kernel development
Major development within RedHat labs
Qemu through the Qemu project
Both are very active
Qemu had 4 releases in 2010
KVM is continuously updated with Linux kernel updates
Summary
About KVM
Advantages of Virtualization
At Home
Outline
1
About KVM
What is KVM
2
Advantages of Virtualization
At Home
At Work (SO)
At Work (ME)
3
Using KVM
Plain Qemu
Using libvirt
4
Use Cases
Example Use Cases
Using KVM
Use Cases
Summary
About KVM
Advantages of Virtualization
Using KVM
Use Cases
At Home
Why Virtualization
Test out new operating systems (new Ubuntu release)
Summary
About KVM
Advantages of Virtualization
Using KVM
Use Cases
At Home
Why Virtualization
Test out new operating systems (new Ubuntu release)
Isolate dangerous applications (malware-sensitive
applications)
Demo’s follow later
Summary
About KVM
Advantages of Virtualization
At Work (SO)
Outline
1
About KVM
What is KVM
2
Advantages of Virtualization
At Home
At Work (SO)
At Work (ME)
3
Using KVM
Plain Qemu
Using libvirt
4
Use Cases
Example Use Cases
Using KVM
Use Cases
Summary
About KVM
Advantages of Virtualization
Using KVM
At Work (SO)
Why Virtualization
Simple full-system backups (disk images)
Use Cases
Summary
About KVM
Advantages of Virtualization
Using KVM
At Work (SO)
Why Virtualization
Simple full-system backups (disk images)
Server running multiple servers (cheaper)
Use Cases
Summary
About KVM
Advantages of Virtualization
Using KVM
Use Cases
At Work (SO)
Why Virtualization
Simple full-system backups (disk images)
Server running multiple servers (cheaper)
Easy testing (snapshot, try upgrade, rollback, ...)
Summary
About KVM
Advantages of Virtualization
Using KVM
Use Cases
Summary
At Work (SO)
Why Virtualization
Simple full-system backups (disk images)
Server running multiple servers (cheaper)
Easy testing (snapshot, try upgrade, rollback, ...)
Desktop virtualization (provisioning, patches, upgrades, ...)
Demo’s follow later
About KVM
Advantages of Virtualization
At Work (ME)
Outline
1
About KVM
What is KVM
2
Advantages of Virtualization
At Home
At Work (SO)
At Work (ME)
3
Using KVM
Plain Qemu
Using libvirt
4
Use Cases
Example Use Cases
Using KVM
Use Cases
Summary
About KVM
Advantages of Virtualization
Using KVM
Use Cases
At Work (ME)
Decouple hardware from software (migration)
Summary
About KVM
Advantages of Virtualization
Using KVM
Use Cases
At Work (ME)
Decouple hardware from software (migration)
Elevate security requirements (disk encryption, host
access, ...)
Summary
About KVM
Advantages of Virtualization
Using KVM
Use Cases
Summary
At Work (ME)
Decouple hardware from software (migration)
Elevate security requirements (disk encryption, host
access, ...)
Simplified multi-system management (but requires
additional tools)
Sorry, no demo’s on this part due to too little available resources
About KVM
Advantages of Virtualization
Plain Qemu
Outline
1
About KVM
What is KVM
2
Advantages of Virtualization
At Home
At Work (SO)
At Work (ME)
3
Using KVM
Plain Qemu
Using libvirt
4
Use Cases
Example Use Cases
Using KVM
Use Cases
Summary
About KVM
Advantages of Virtualization
Using KVM
Use Cases
Plain Qemu
Plain Qemu Commands
Most advanced, yet least user friendly aspect
Let us demonstrate:
Create a (virtual) disk
Boot a CD
Install a new operating system
Create a new image with the first image as base
Play with the new operating system
We’ll pick Ubuntu 10.04, but first...
Summary
About KVM
Advantages of Virtualization
Using KVM
Plain Qemu
Setup Qemu Networking
Virtual network with virtual hub/switch
Connect virtual network with real network
Allow Internet access from virtual network
Example
modprobe t u n
modprobe kvm−i n t e l
t u n c t l −b −u s w i f t −t tap0
i f c o n f i g tap0 1 9 2 . 16 8. 10 0.1 up
vde_switch −−numports 4 −−hub −−mod 777 \
−−group users −−t a p tap0 −d
s h a r e _ i n t e r n e t . sh
echo 1 > / sys / k e r n e l /mm/ ksm / run
Okay, now onto the demonstration
Use Cases
Summary
About KVM
Advantages of Virtualization
Using KVM
Plain Qemu
Create disk image
Create an empty disk of about 20Gb
Use type qcow2 (copy-on-write)
Example
qemu−img c r e a t e −f qcow2 imagename . img 20G
Use Cases
Summary
About KVM
Advantages of Virtualization
Using KVM
Use Cases
Summary
Plain Qemu
Boot from ISO
Boot from a downloaded ISO
The default console can be accessed using vnc
Install the Ubuntu 10.04 operating system
Example
kvm \
−n e t n i c , model= v i r t i o , macaddr = 0 0 : 1 1 : 2 2 : 3 3 : 4 4 : a0 , v l a n =0 \
−n e t vde , v l a n =0 \
−d r i v e f i l e =imagename . img , i f = v i r t i o , boot=on \
−usb −usbdevice t a b l e t −k n l −be −m 512 \
−cdrom / s r v / v i r t / media / ubuntu −10.04.1− desktop−amd64 . i s o \
−boot d
About KVM
Advantages of Virtualization
Using KVM
Use Cases
Plain Qemu
Use a base image
Now we use the image as a base...
and then boot the new image
Example
qemu−img c r e a t e −f qcow2 \
−o b a c k i n g _ f i l e =imagename . img t e s t . img
We can always rebase such images when we want to
Summary
About KVM
Advantages of Virtualization
Using libvirt
Outline
1
About KVM
What is KVM
2
Advantages of Virtualization
At Home
At Work (SO)
At Work (ME)
3
Using KVM
Plain Qemu
Using libvirt
4
Use Cases
Example Use Cases
Using KVM
Use Cases
Summary
About KVM
Advantages of Virtualization
Using KVM
Use Cases
Using libvirt
What is libvirt?
Open-source API for platform virtualization (supporting
KVM, Xen, VMWare)
Used by oVirt, virt-manager, virsh
Backed by RedHat
Advantages over ’regular’ Qemu:
Summary
About KVM
Advantages of Virtualization
Using KVM
Use Cases
Using libvirt
What is libvirt?
Open-source API for platform virtualization (supporting
KVM, Xen, VMWare)
Used by oVirt, virt-manager, virsh
Backed by RedHat
Advantages over ’regular’ Qemu:
’Domains’ run in the background
Summary
About KVM
Advantages of Virtualization
Using KVM
Use Cases
Using libvirt
What is libvirt?
Open-source API for platform virtualization (supporting
KVM, Xen, VMWare)
Used by oVirt, virt-manager, virsh
Backed by RedHat
Advantages over ’regular’ Qemu:
’Domains’ run in the background
Technology-agnostic
Summary
About KVM
Advantages of Virtualization
Using KVM
Use Cases
Using libvirt
What is libvirt?
Open-source API for platform virtualization (supporting
KVM, Xen, VMWare)
Used by oVirt, virt-manager, virsh
Backed by RedHat
Advantages over ’regular’ Qemu:
’Domains’ run in the background
Technology-agnostic
Simple(r) interface
Summary
About KVM
Advantages of Virtualization
Using KVM
Use Cases
Using libvirt
Setting up the network
Libvirt does not support VDE yet, so requires bridging
setup
Bridging creates central connection points (bridge) where
multiple tap devices can be attached on
Summary
About KVM
Advantages of Virtualization
Using KVM
Use Cases
Using libvirt
Setting up the network
Libvirt does not support VDE yet, so requires bridging
setup
Bridging creates central connection points (bridge) where
multiple tap devices can be attached on
Setup is like before, but now with additional commands:
Example
b r c t l addbr br0
b r c t l a d d i f br0 tap0
Summary
About KVM
Advantages of Virtualization
Using KVM
Use Cases
Using libvirt
Create a virtual environment
Give the runtime a name
Use the bridge:br0 networking interface
Example
v i r t − i n s t a l l −−connect qemu : / / / system −n win7 \
−r 1024 −−vcpus=2 \
−−d i s k path = / s r v / v i r t / win7 / win7base . img , s i z e =20 \
−−vnc −−noautoconsole −−os−t y p e windows \
−−a c c e l e r a t e −−network b r i d g e : br0 \
−−cdrom / s r v / v i r t / media / win7dvd . i s o
Summary
About KVM
Advantages of Virtualization
Using KVM
Use Cases
Using libvirt
Working with a virtual environment
The virsh tool supports various command-line options
Summary
About KVM
Advantages of Virtualization
Using KVM
Use Cases
Summary
Using libvirt
Working with a virtual environment
The virsh tool supports various command-line options
The virt-viewer tool is a VNC viewer that integrates with the
domain names
About KVM
Advantages of Virtualization
Using KVM
Use Cases
Summary
Using libvirt
Working with a virtual environment
The virsh tool supports various command-line options
The virt-viewer tool is a VNC viewer that integrates with the
domain names
The virt-manager tool is a all-in-one graphical tool
About KVM
Advantages of Virtualization
Using KVM
Use Cases
Summary
Using libvirt
Working with a virtual environment
The virsh tool supports various command-line options
The virt-viewer tool is a VNC viewer that integrates with the
domain names
The virt-manager tool is a all-in-one graphical tool
Guess which one we’ll show ;-)
About KVM
Advantages of Virtualization
Example Use Cases
Outline
1
About KVM
What is KVM
2
Advantages of Virtualization
At Home
At Work (SO)
At Work (ME)
3
Using KVM
Plain Qemu
Using libvirt
4
Use Cases
Example Use Cases
Using KVM
Use Cases
Summary
About KVM
Advantages of Virtualization
Using KVM
Use Cases
Summary
Example Use Cases
Testing
Try out a new operating system
Try out a large upgrade
Temporarily install garbage
Try out a clean-up
We need:
qcow2 copy-on-write support (can be against a partition or
lvm snapshot), or
storage snapshoting
About KVM
Advantages of Virtualization
Using KVM
Use Cases
Example Use Cases
Development Support
Development of multi-platform supporting application
Test application on several distributions or versions
Regression tests on new, upgrade, downgrade and other
scenarios
We need:
Multiple virtual instances
Large environment management tooling, like cfengine or
jobscheduler
qcow2 copy-on-write support
Summary
About KVM
Advantages of Virtualization
Using KVM
Use Cases
Example Use Cases
Uninterruptible Process
Long-running process (for instance, video rendering)
You need a safepoint in case you need to make a
potentially destructive decision
We need:
qcow2 savevm and loadvm support
Summary
About KVM
Advantages of Virtualization
Using KVM
Use Cases
Example Use Cases
V2P or P2V
You want to migrate/copy your physical system in a virtual
one (P2V), or
You want to migrate/copy your virtual system to a physical
(V2P)
We need:
Good backup/restore software ;-)
Summary
About KVM
Advantages of Virtualization
Using KVM
Use Cases
Summary
So now we know
a bit more on virtualization
how to run virtual instances ourselves
a couple of benefits of using virtual environments
Summary
About KVM
?
Advantages of Virtualization
Using KVM
Use Cases
Summary