1.
James Bulpin
XenServer CTO
James.Bulpin@citrix.com
Xen Project User Summit - Xen, XenServer,
and XAPI: What’s the Difference?
@JamesBulpin
Russell Pavlicek
Xen Project Evangelist
Russell.Pavlicek@XenProject.org
@RCPavlicek

2.
• Linux author/evangelist/speaker since 1995
• Formerly FOSS columnist for Infoworld,
Processor, panelist on The Linux Show
webcast, speaker at ~50 FOSS conferences
• Xen Project Evangelist hired by Citrix in
January 2013
• Xen user/admin/integrator/ tester since
2004
• XenSource startup veteran
• Leads Citrix XenServer technical strategy
About the Speakers...
Russ James

3.
• …until you ask them
• Some days, it seems there is more confusion about the
naming conventions than about the software
• When some people talk about “Xen”, they mean “Xen
Project”, but others mean “XenServer”, and yet others
“XAPI”
• It is time to clear up the confusion
The Problem: Everyone Knows What Xen Is...

4.
• The Leading Open Source Hypervisor
• Open Source – now and always!
• A Linux Foundation Collaborative Project since April 2013
• Celebrating its 10th anniversary
• Home for several subproject teams
What is the Xen Project?

5.
Xen Project: A Short History

6.
• The Xen Hypervisor: the main game
• PVOPS: (not technically a subproject, but…) allows Linux to
run paravirtualized on a hypervisor (Xen, VMware VMI, …)
• The Xen ARM Hypervisor: branching into new architecture
• XAPI Project: more on this later
• Mirage OS: focused appliances built on a specialized library
operating system (in incubation)
The Xen Project Subproject Teams

7.
Xen Hypervisor: The Crux of the Xen Project
• Type 1 Hypervisor: Does not run in
the kernel
• VMs compete with other VMs for
resources, not with processes
• Architecture emphasizes security
• Uses toolstacks for Control Domain
to talk to Hypervisor
• Default is XL (improved on XM)
• Libvirt/VIRSH option
• No native GUI

8.
Xen Project Corporate Members
Is your company listed here? Should it be?
If you are heavily invested in Xen, consider project membership.

9.
• Nexus of information regarding the Xen Project
• Newly revamped and revised in April 2013
• Access to Articles, Blogs, Wiki, Q&A, Mailing Lists, etc.
• New monthly newsletter with highlights from the
community
• Sign up for the website and newsletter today, if you
haven’t already!
XenProject.org: The Hub of Information

10.
Xen Project Mascot
Because a cute panda is a terrible thing to waste

11.
• A distribution of Xen, the XAPI toolstack, Linux and other
components
• A “shrink-wrapped”, ready to run, virtualization platform
• Builds on basic Xen virtualization to provide high level
management:
Networking High availability
Storage Cluster management
User accounts Performance monitoring
If That’s Xen, What is XenServer?

12.
• Started as “XenEnterprise”, a product of XenSource Inc.
– First released in 2006
– Initially a proprietary product built on top of the open-source
Xen hypervisor
• Evolved into XenServer, a product of Citrix
– Now up to version 6.2 (released June 2013)
• Became an open-source project in 2013
XenServer – a brief history

13.
Xen
Linux Kernel XAPI
Storage
Manager
XenServer
Tools (PV
drivers)
HA
CentOS 5.x
AD Integration
XenCenter
XenServer – previously
Transfer VM
CIM Server
Qemu
Proprietary
OSS, public dev
Key:
OSS, non-public dev

14.
Xen
Linux Kernel XAPI
Storage
Manager
XenServer
Tools (PV
drivers)
HA
CentOS 5.x
AD Integration
XenCenter
XenServer – after open sourcing
Proprietary
OSS
Key:
Transfer VM
CIM Server
Qemu

15.
• A Citrix-led project
• Removing barriers to collaboration
• Roadmaps, designs and architectural plans discussed in the
open
• All code is public; contributions via mailing list and Github
pull requests
• More efficient ecosystem through access to design, code
and developers
XenServer.org – the open-source project

16.
#1 a set of components
– XenCenter UI
– Windows PV drivers
– HA daemon
– vncterm
– …
#2 an integration/distribution of
components
– Choice of component versions
– Backporting of patches
– Configuration and tuning
– Packaging
– …
XenServer.org – two parts to it
But Xen and XAPI are Xen Project
components so XenServer developers
contribute to those projects and the results
are integrated and packaged into XenServer

17.
• Citrix’s product release from the
Open Source project code
• Made available to all for free
• Optional commercial support offering
from Citrix
Citrix XenServer

18.
• A toolstack for managing Xen system
– The xapi daemon and its friends; the “xe” CLI
• Works at a higher level than the Xen Project toolstack
– Clustering, storage/network management, host setup, …
• Open-sourced by Citrix in 2009
• Now part of the Xen Project in the Linux Foundation
• Useful for Xen users who want richer API-driven
management (such as under OpenStack clouds)
So What is XAPI?

19.
“Xen Cloud Platform” – an overloaded term
• Meaning 1: a synonym for XAPI (particularly for packaged
versions)
• Meaning 2: XenServer-like binary ISOs
– Built to provide a distribution for xapi without non-FOSS
XenServer pieces
– Provided a wider feature set than the free edition of Citrix
XenServer which had certain features disabled
What is XCP?

20.
• XCP and open-source XenServer will merge
– XenServer no longer disables features for non-paying users
• Users of XCP v1.6 are able to upgrade to XenServer
• XCP users will be getting a better deal than they had before
– No more delays to XCP releases
– Timely hotfixes that can be easily installed,
– A product that's even more open than it was before.
XCP (the ISO) is no more

21.
And you thought this talk would be easy… ;)
And Now It Is QUIZ TIME!

22.
Question: Xen, XenServer, or XAPI?

23.
Answer: Xen (Xen Project Mascot)

24.
Question: Xen, XenServer, or XAPI?

25.
Answer: XenServer (XenCenter)

26.
Question: Xen, XenCenter, or XAPI?

27.
Answer: XenServer

28.
Question: Xen, XenCenter, or XAPI?

29.
Answer: Xen and XAPI

30.
$ xe vdi-create
name-label=LogDisk
sr-uuid=6021e2b0-c72e-6e9e-01cc-ba3ed4f68be9
virtual-size=10GiB type=user
$ xe vbd-create device=2 type=Disk
vm-uuid=d2f6e2cd-8a98-7e1c-7a46-f4dcff3b56ce
vdi-uuid=cdd63557-89ad-4011-b638-e063f8b08298
$ xe vm-start vm=MyDHCPServer
Question: Xen, XenServer, or XAPI?

31.
$ xe vdi-create
name-label=LogDisk
sr-uuid=6021e2b0-c72e-6e9e-01cc-ba3ed4f68be9
virtual-size=10GiB type=user
$ xe vbd-create device=2 type=Disk
vm-uuid=d2f6e2cd-8a98-7e1c-7a46-f4dcff3b56ce
vdi-uuid=cdd63557-89ad-4011-b638-e063f8b08298
$ xe vm-start vm=MyDHCPServer
Answer: XAPI (xe CLI)

32.
# xl create -c /etc/xen/wheezy64
# xen-create-image
--genpass=0 --memory=1024M --noswap --dhcp
--password="xenroot" --pygrub --size=8G
--vcpus=2 --arch=amd64 --bridge=virbr0
--hostname=wheezy64 --lvm=vms
--mirror=http://cdn.debian.net/debian
--install-method=debootstrap
--dist=wheezy
Question: Xen, XenServer, or XAPI?

33.
# xl create -c /etc/xen/wheezy64
# xen-create-image
--genpass=0 --memory=1024M --noswap --dhcp
--password="xenroot" --pygrub --size=8G
--vcpus=2 --arch=amd64 --bridge=virbr0
--hostname=wheezy64 --lvm=vms
--mirror=http://cdn.debian.net/debian
--install-method=debootstrap
--dist=wheezy
Answer: Xen (xl and command line utility)

34.
Extra Credit: Xen, XenServer, or XAPI?

35.
Answer: Trick Question!
Used by Xen and XenServer, but a separate
project entirely!

36.
Thank You!
Slides available under CC-BY-SA 3.0
From www.slideshare.net/xen_com_mgr
@RCPavlicek
@JamesBulpin
@Xen_Org
• News: blog.XenProject.org
• Web: XenProject.org / www.XenServer.org
– Help for IRC, Lists, …
– Stackoverflow-like Q&A
• Wiki: wiki.XenProject.org
• Presentations: slideshare.net/xen_com_mgr
• Videos: vimeo.com/channels/xen